Vector recall at k

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

No contradiction with annotations (readOnlyHint=true). The description adds context about using brute-force ground truth and function-form distance, but does not disclose performance impact or side effects. It adequately describes the read-only nature.

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 concise with two sentences, front-loading the core purpose. No unnecessary words, though it could slightly expand parameter context.

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?

Given 8 parameters, low schema coverage, and an existing output schema, the description is insufficient. It omits details about how parameters affect behavior and does not mention return values or sampling methodology.

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 only 13%, yet the description adds no parameter explanations (e.g., meaning of k, sample_size, metric). It only mentions requiring the vector extension. The description fails to compensate for the low schema 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?

The description clearly states the tool measures recall@k of a pgvector index against brute-force ground truth, specifying the verb 'measure' and the resource 'existing pgvector index'. It distinguishes from sibling tools like vector_search or analyze_hnsw_recall by focusing on recall evaluation.

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 no guidance on when to use this tool versus alternatives such as analyze_hnsw_recall or tune_vector_index. It only mentions a prerequisite (vector extension) but lacks context for decision-making.

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