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agentmail-collaboration

Use when collaborating with another human or agent over AgentMail/email-like transports. Enforces AgentBook lookup, scoped trust, outbound validation, and safe handoff practices.

Quality

85%

Does it follow best practices?

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SecuritybySnyk

Low

Low-risk findings worth noting

SKILL.md
Quality
Evals
Security

Quality

Content

88%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 well-crafted protocol skill body: lean, dense with non-obvious domain specifics, and two clearly sequenced workflows with explicit validation checkpoints and a verification checklist. The only gaps are missing executable examples for Svix signature verification and the AgentMail labeling API, and inline content that a larger skill might move to reference files.

DimensionReasoningScore

Conciseness

The body is lean and every section conveys tool-specific knowledge Claude would not already know (agentbook CLI semantics, Svix raw-body verification caveat, the 1 MB payload omission, unauthenticated event subscription); there is no padding or explanation of familiar concepts.

5 / 5

Actionability

Required Flow and CLI Reference provide copy-paste-ready commands with exit-code semantics ("Exit code `2` or `allowed: false` means do not send"), but Svix verification ("Verify with the webhook secret (`whsec_...`)") and "Label the message via the AgentMail API" lack any executable command or code example.

4 / 5

Workflow Clarity

Both the Required Flow and Inbound Webhook Flow are explicitly ordered with validation checkpoints ("Validate before send", "Stop on denial"), a re-validation feedback loop ("If the content changes, validate again"), and a closing verification checklist — matching the anchor for clear sequence with explicit validation and error-recovery loops.

5 / 5

Progressive Disclosure

Sections are well-organized with clear headers and no buried or dead references, but the ~165-line body keeps content like the Inbound Webhook Flow and CLI Reference inline where a moderately sized skill could split them into reference files, so it falls just short of the clear-overview-with-well-signaled-references anchor.

4 / 5

Total

18

/

20

Passed

Description

78%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 solid third-person description that explicitly covers both what the skill enforces and when to use it, anchored to specific named systems that make it highly distinguishable. Its main weakness is trigger coverage limited to a single collaboration scenario and a slightly abstract closing phrase ("safe handoff practices").

Suggestions

Add concrete trigger phrases for common scenarios, e.g. "when you receive a message from an agent-owned inbox" or "when sending a project update or task request to a collaborator".

Replace the abstract "safe handoff practices" with concrete actions such as "quarantines unknown senders and initiates scoped handshakes".

Include natural synonyms users would say, such as "messaging", "inbox", or "coordinate with another agent", to broaden trigger term coverage.

DimensionReasoningScore

Specificity

"Enforces AgentBook lookup, scoped trust, outbound validation, and safe handoff practices" lists several concrete actions, though "safe handoff practices" is generic and the coverage is mechanism-level rather than comprehensive, matching the anchor for several specific actions with minor gaps.

4 / 5

Completeness

Both what ("Enforces AgentBook lookup, scoped trust, outbound validation...") and when ("Use when collaborating with another human or agent over AgentMail/email-like transports") are explicit, but the when-clause covers a single scenario and could name more concrete trigger phrases.

4 / 5

Trigger Term Quality

Natural terms like "collaborating", "AgentMail", and "email-like transports" are present and would be said by users in this ecosystem, but common variations such as "messaging", "inbox", or "coordinate with an agent" are missing.

4 / 5

Distinctiveness Conflict Risk

The named systems (AgentMail, AgentBook) and email-transport qualifier establish a clear niche with distinct triggers; "collaborating with another human or agent" alone would be broad, but the transport qualifier immediately narrows it to minimal conflict risk.

5 / 5

Total

17

/

20

Passed

Validation

81%

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

Validation — 13 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

metadata_version

'metadata.version' is missing

Warning

metadata_field

'metadata' should map string keys to string values

Warning

frontmatter_unknown_keys

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

Warning

Total

13

/

16

Passed

Repository

timfoo/agentbook

Path

skills/agentmail-collaboration/SKILL.md

Reviewed

Table of Contents

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