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

With no annotations, the description carries the burden of disclosing behaviors. It mentions the API key requirement and clearly lists the output fields, making the read-only nature evident. However, it does not address potential pagination or sorting behaviors, which is a minor gap.

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 two concise sentences, front-loaded with the verb 'List' and resource 'diagrams'. The parenthetical field list and auth requirement add essential information without any redundancy or fluff.

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?

As a simple list tool with 0 params and no output schema, the description sufficiently conveys the primary purpose, the fields returned, and the auth requirement. It does not specify sorting or pagination, but these are not critical for a basic listing operation.

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 tool has zero parameters and the schema reflects this. With 0 params, the baseline is 4, and the description adds no parameter info because none is needed. The field list in the description compensates for the lack of an output 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 tool lists the authenticated user's saved diagrams, specifying the exact fields returned (id, title, type, visibility, updatedAt). This distinguishes it from siblings like get_diagram (single diagram) and search_diagrams (search-based retrieval).

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 usage for retrieving one's own diagrams but does not explicitly mention alternatives or when not to use this tool. It provides clear context (auth requirement) but lacks direct differentiation from similar list/search tools.

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