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

The readOnlyHint annotation already signals a safe read operation. The description adds valuable context: the enterprise plan requirement and the exact API endpoint (GET /api/v1/sites/goals), which goes beyond the annotation's basic safety signal.

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 three short sentences that front-load the action, state an access constraint, and provide the endpoint. No wasted words; every piece adds value.

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 simple list tool with one parameter and a readOnly annotation, the description covers purpose, access, and endpoint. It doesn't specify the response shape, but the absence of an output schema and the straightforward nature of listing goals make this adequate.

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% coverage for the single parameter site_id, including an example ('example.com'). The description itself doesn't add parameter details, so the baseline 3 is appropriate since the schema already does the heavy lifting.

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 'List the goals (conversions) configured for a site,' specifying the verb, resource, and scope. It distinguishes itself from siblings like plausible_breakdown or plausible_timeseries by targeting the 'goals' resource, and the endpoint reference adds specificity.

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 mentions 'Requires an enterprise plan,' which is a key prerequisite for using this tool, and the API endpoint implies when it applies. While it doesn't explicitly name alternatives, the purpose is clear enough for an agent to infer appropriate use.

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