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agentmail

Email infrastructure for AI agents. Create accounts, send/receive emails, manage webhooks, and inspect billing balance via the AgentMail API.

Quality

72%

Does it follow best practices?

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SecuritybySnyk

Low

Low-risk findings worth noting

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tessl review fix ./skills/agentmail/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

61%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A highly actionable, well-organized API guide with executable curl and TypeScript examples throughout. Its weaknesses are redundant repetition of the retired-API/billing caveats, implicit rather than explicit validation in the polling workflows (no timeout-exhaustion or destructive-op checks), and prose-only guidance for billing and webhook signature verification.

Suggestions

Consolidate the retired /v1/karma and 'verify current billing' caveats into a single 'Deprecated / verify-current' note instead of repeating them across four sections.

Add explicit timeout-exhaustion handling to the polling loops (e.g. throw or report when the 30/60 iterations complete without a match) and a validation step before destructive operations like account deletion.

Provide the concrete curl command for the billing balance endpoint and a code snippet for HMAC-SHA256 webhook signature verification, since both are currently prose-only.

DimensionReasoningScore

Conciseness

The curl and SDK examples are lean, but the retired '/v1/karma' caveat is repeated in four places ('historical /v1/karma contract', 'not the historical karma table', 'historical Karma types are not current') and hedging phrases like 'must be verified' and 'Verify current billing' pad several sections. Mostly efficient but could be tightened matches the 3 anchor; it is not 4 because the repetition is a noticeable amount of redundant tokens.

3 / 5

Actionability

Mostly executable guidance: copy-paste-ready curl commands with timeouts, runnable TypeScript snippets, an endpoint table, and complete polling-loop examples. It falls short of 5 because the billing section directs to 'the current documented read-only billing endpoint' without a concrete command, and webhook signature verification is described only in prose with no code.

4 / 5

Workflow Clarity

The two multi-step patterns (signup + poll for verification, send + await reply) have a clear sequence but only implicit checkpoints — the loops silently expire after 30/60 iterations with no timeout-exhaustion handling, and the destructive delete-account operation has no validation workflow. Steps listed with validation gaps matches the 3 anchor; it is not 4 because these checkpoint gaps are more than minor.

3 / 5

Progressive Disclosure

No bundle files exist, and the body is well-sectioned with clear headers and a single, clearly signaled one-level-deep external reference ('[current billing and API docs](https://api.theagentmail.net/docs)'). Good structure with minor organization gaps matches the 4 anchor — the inline Types and SDK sections could arguably live in a separate reference file.

4 / 5

Total

14

/

20

Passed

Description

71%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A specific, well-scoped description that clearly states what the skill does with concrete API actions. Its main weakness is the complete absence of 'when to use' trigger guidance, which caps completeness and leaves natural trigger phrases (inbox, verification codes) uncovered.

Suggestions

Add an explicit 'Use when...' clause, e.g. 'Use when an agent needs a real email address to sign up for services, receive verification codes, or send transactional email.'

Include natural trigger variations users would actually say, such as 'inbox', 'verification email', or 'get an email address for the agent'.

Mention the service domain (@theagentmail.net) to further distinguish it from generic email or the separate agentmail.to service.

DimensionReasoningScore

Specificity

The description lists four concrete, distinct actions — 'Create accounts, send/receive emails, manage webhooks, and inspect billing balance' — which comprehensively covers the skill's API surface. It matches the 5 anchor (multiple specific concrete actions, comprehensive coverage) rather than 4, since no capability area is missing.

5 / 5

Completeness

The 'what' is clearly stated ('Email infrastructure for AI agents... via the AgentMail API') but there is no 'Use when...' clause or equivalent explicit trigger guidance, capping completeness at 3 per the judging guidelines. It is not 2 because the 'what' is concrete, not vague.

3 / 5

Trigger Term Quality

Natural phrases like 'send/receive emails', 'accounts', 'webhooks', and 'billing balance' are present, but common variations users would say are missing (inbox, verification codes, email address for signups, .net domain keywords). Good coverage with a few natural terms missing fits the 4 anchor, not 5's comprehensive synonym coverage.

4 / 5

Distinctiveness Conflict Risk

Naming 'the AgentMail API' and 'Email infrastructure for AI agents' carves a clear niche, though generic email-related skills could still overlap. Mostly distinct with minor overlap risk matches the 4 anchor; it lacks the fully distinct trigger phrasing of a 5.

4 / 5

Total

16

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

sickn33/agentic-awesome-skills

Path

skills/agentmail/SKILL.md

Reviewed

Table of Contents

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