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

With no annotations, the description carries the burden and mostly delivers: it discloses the multi-client behavior, the fine-grained output (per-client verdicts, rule, why, fix), and the no-account requirement. It doesn't explicitly discuss side effects, but an auditing tool's read-only nature is clearly implied and no auth/rate-limit surprises are indicated.

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?

Three tight sentences: what the tool does, what it returns, when to use it, and access requirements. Every sentence contributes and the most important action verb is front-loaded.

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?

With only one input parameter and a rich description of the return behavior (per-client verdicts, problems, rules, fixes), plus use cases and access requirements, an agent has everything needed to select and invoke this tool correctly.

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?

The schema documents the html parameter as 'the full HTML of the email signature,' and the description's wording 'Audit any email-signature HTML' aligns with that. Since schema coverage is 100%, the baseline of 3 applies; no additional format or example detail is provided beyond the schema.

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?

The description states a specific verb ('Audit'), a precise resource ('email-signature HTML'), and names the exact target clients (Gmail, Outlook, iOS Mail, etc.). This clearly distinguishes it from the sibling tools like create_email_signature or list_signature_templates.

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?

Explicitly gives trigger scenarios: when a signature is broken, images don't render, Outlook layout fails, or before sending. It does not name alternatives or provide exclusion criteria, but the when-to-use guidance is unambiguous and actionable.

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