unphurl-mcp

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It excels by detailing security behavior ('the response is always the same regardless of whether the email exists, is already verified, or was rate limited'), rate limiting ('Rate limited to 3 requests per email per hour'), and authentication requirements ('This tool does not require an API key'). These are all valuable behavioral traits not deducible from the schema alone.

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?

The description is perfectly structured and front-loaded: the first sentence states the core purpose, followed by usage context, security behavior, rate limits, and authentication details. Every sentence adds essential information with zero waste, making it easy for an AI agent to parse quickly.

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?

For a single-parameter tool with no annotations and no output schema, the description provides comprehensive context. It covers purpose, usage guidelines, security behavior, rate limits, and authentication requirements—everything an agent needs to correctly invoke this tool without needing additional structured data.

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 input schema has 100% description coverage, so the baseline is 3. The description adds meaningful context beyond the schema by explaining why the email parameter matters ('Email address of the account that needs verification') and tying it to the verification process. However, it doesn't provide additional format constraints or examples beyond what's in 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 clearly states the specific action ('resend the email verification link') and the target resource ('for an existing Unphurl account'). It distinguishes itself from sibling tools like 'signup' (which creates accounts) and 'create_profile' (which manages profiles) by focusing specifically on verification link renewal for existing accounts.

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?

The description provides explicit guidance on when to use this tool ('when a user signed up but their verification link expired (links are valid for 24 hours) and they need a new one') and includes important context about prerequisites ('The user's API key won't work until their email is verified'). It also implicitly distinguishes from alternatives like 'signup' by focusing on existing accounts rather than new account creation.

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