email_verify

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare safety (readOnlyHint, idempotentHint). Description adds rich behavioral context: specific checks (syntax, MX, disposable, role, free provider), edge cases (plus-tag stripping, role types), rate limits, and output fields. No contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Well-structured but moderately long. Every sentence adds value, though could be slightly more concise. Good front-loading of purpose and usage.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given complexity (multi-check composite tool) and existence of output schema, description is complete: covers all checks, usage, limitations, rate limits, and output fields. Agent can fully understand behavior.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage 100% and schema description already explains the email parameter. Description adds value with examples, required '@' presence, and implied format. Slightly above baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clear verb+resource: 'email validation' combining multiple checks. Explicitly distinguishes from siblings by stating it replaces email_mx, email_disposable, and manual role parse in one call.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit usage contexts: 'Use BEFORE adding an email to a contact list...' and clear what it does NOT do (SMTP deliverability) with rationale and alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.