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

Annotations already provide readOnlyHint=true, so the safety profile is covered. The description adds the concrete Autumn API endpoint and method, POST /v1/features.get, which is useful implementation context, but it provides no detail on errors, not-found behavior, or response shape.

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 short sentences with the main action front-loaded and no filler. The endpoint sentence adds a useful API detail without obscuring the primary instruction, making this an appropriately sized and well-structured description.

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 one-parameter read-only lookup, the description plus schema is nearly sufficient for an agent to invoke the tool correctly. The main gap is the lack of any stated return or error behavior, especially since no output schema exists to fill that in.

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 100%, and the single parameter feature_id is already documented as 'The ID of the feature.' The description adds no additional parameter meaning, so the baseline score of 3 applies.

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 the exact action 'Fetch', the resource 'single feature', and the lookup criterion 'by id'. This clearly distinguishes it from list_features for bulk retrieval, so an agent can select it correctly without inspecting other schemas.

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 implies this tool is for retrieving one feature when its ID is known, but it never explicitly names alternatives or states when not to use it. The context is enough for simple selection, but there is no explicit routing or exclusion guidance.

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