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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the behavioral context that this is a prerequisite lookup step and that it returns the complete spec needed for call_api. It doesn't describe pagination or error behavior, but for a read-only spec-fetch tool the annotations carry the main burden.

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?

Two sentences, no filler. The core purpose is front-loaded, and the usage directive is placed at the end where it reinforces the workflow.

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 2-parameter read-only lookup tool with no output schema, the description covers the purpose, the source, and the workflow position. It could mention what happens if the endpoint isn't found, but the explicit 'always call this before call_api' directive makes the tool's role complete enough for an agent.

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 description coverage is 0%, so the schema provides only names and types. The description says the tool returns the spec for 'one endpoint' and implies service and endpoint identify it, but it doesn't explain the expected format of the endpoint value (e.g., path string, ID). Baseline 3 is fair because the description adds some context but doesn't fully compensate for the 0% coverage.

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?

States a specific verb ('Get'), a specific resource ('full specification for one endpoint'), and the source ('from search_apis results'). It clearly distinguishes itself from siblings by naming the prerequisite search_apis and the downstream call_api.

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 instructs when to use it: 'Always call this before call_api unless you already have the spec.' This is a clear directive that also names the alternative (call_api) and the condition that bypasses this tool.

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