verify-email

Verify if an email address is valid and deliverable

Quality

73%

Does it follow best practices?

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Adds up to 20 points to the overall score

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Securityby

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./skills/lead-generation/capabilities/verify-email/SKILL.md

Quality

Content

81%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.

The body is a strong, highly actionable reference: executable commands, complete response documentation, a result-interpretation table, and real error-recovery guidance. Its main weaknesses are token duplication (the same curl command shown four times) and a response-field reference section that could be offloaded to a bundled file.

Suggestions

Replace the verbatim curl commands in the Examples section with just the query payloads or a note that only the email changes, cutting roughly 15 lines of duplication.

Move the detailed Hunter/Tomba response-field listings into a references/ file (e.g. references/response-fields.md), keeping only the status/score essentials inline.

Delete the restated one-liner "Check if an email address is valid, exists, and can receive mail. Prevent bounces before sending." — it duplicates the frontmatter description without adding information.

Dimension	Reasoning	Score
Conciseness	Most sections (setup, parameters, error handling, tips) are lean and earn their tokens, but the full curl command appears four times — the Examples section repeats the Usage commands verbatim with only the email swapped — and "Check if an email address is valid, exists, and can receive mail" restates the frontmatter description. This is the "mostly efficient but could be tightened" of anchor 3 rather than the minor trim of anchor 4.	3 / 5
Actionability	Fully executable, copy-paste-ready curl commands with auth headers and JSON bodies for both Hunter and Tomba, a credentials bootstrap with a concrete fallback (`npx gooseworks login`), and worked examples mapping user requests to commands. This matches anchor 5 exactly.	5 / 5
Workflow Clarity	A simple single-purpose skill with an unambiguous action: credential setup (with explicit fallback if credentials are missing) → verify → interpret result via the Result Types table → handle errors with explicit retry guidance (429 "wait and retry", Tomba greylisted "retry after a few minutes"). The single-action and error-recovery feedback loops satisfy the simple-skill exception for a 5; no destructive or batch operation applies.	5 / 5
Progressive Disclosure	No bundle files exist, and the ~120-line body is organized into clear, scannable sections covering exactly one task. The ~30 lines of Hunter/Tomba response-field reference could be split into a separate reference file, which is the minor placement gap of anchor 4 rather than the inline-bloat of anchor 3.	4 / 5
	Total	17 / 20 Passed

Description

53%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.

The description states a clear, concrete capability but is a bare minimum: no trigger guidance, few natural synonyms, and no enumeration of the actual verification checks. Adding a "Use when..." clause and natural user phrasings would lift completeness and trigger-term quality substantially.

Suggestions

Add an explicit trigger clause, e.g. "Use when the user wants to check if an email is real, verify addresses before sending, clean an email list, or avoid bounces in cold outreach."

Include natural synonyms and phrasings users actually say — "is this email real", "email checker", "bounce", "email list cleaning" — to improve trigger-term coverage.

Briefly enumerate the concrete checks performed (syntax, domain/MX records, mailbox existence) to raise specificity from one action to comprehensive coverage.

Dimension	Reasoning	Score
Specificity	"Verify if an email address is valid and deliverable" names the email-verification domain and one concrete action, but stops there — it doesn't mention the underlying checks (syntax, domain/MX, mailbox) that would make coverage comprehensive. It clearly exceeds the generic anchor 2 and falls short of anchor 4's "several specific actions".	3 / 5
Completeness	The "what" is clear (verify validity and deliverability of an email), but there is no "Use when..." clause or equivalent trigger guidance, which caps completeness at 3 per the judging guidelines. It is not a 4 because the "when" is entirely absent rather than merely implicit.	3 / 5
Trigger Term Quality	Relevant keywords like "email address", "valid", and "deliverable" are present, but common natural phrases users would say — "is this email real", "check this email", "bounce", "email list" — are missing. This matches anchor 3 (some relevant keywords, missing variations) rather than anchor 4's good coverage.	3 / 5
Distinctiveness Conflict Risk	Email deliverability verification is a distinct niche unlikely to trigger for unrelated skills, so it mostly clears anchor 4. It is not a 5 because the single short sentence provides no explicit distinct triggers that would fully separate it from neighboring email- or outreach-related skills.	4 / 5
	Total	13 / 20 Passed

Validation

93%

Warnings & errors only

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

Criteria	Description	Result
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	15 / 16 Passed

Repository: gooseworks-ai/goose-skills
Path: skills/lead-generation/capabilities/verify-email/SKILL.md
Commit: cc3e518

Reviewed: 7 days ago

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