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

Even though annotations already declare readOnlyHint, idempotentHint, and destructiveHint, the description adds new behavioral context: the tool is read-only, cached for up to an hour, requires no key or account, and total_matches signals truncation by limit. This goes beyond what annotations provide and helps the agent understand response semantics and freshness. No contradictions with annotations.

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 four sentences, each carrying distinct value: purpose, usage context, return fields and truncation signal, alternative tool, and access/caching note. It is front-loaded with purpose and usage, and no sentence is redundant with the schema or annotations. It is dense yet concise, earning a 5.

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 there is no output schema, the description compensates by listing the return fields (name, chamber, party, state, trade and filing counts, buy/sell split, dollar volume range, coldpine.io page) and explaining total_matches. It also covers access requirements and caching. For a search tool with 3 parameters and no output schema, this is fully sufficient for an agent to invoke it correctly and interpret results.

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% (all three parameters have descriptions in the schema). The description adds minimal parameter-specific meaning: it reiterates the query is by 'full or partial name' (already in schema) and implies limit affects total_matches, but does not explain limit/chamber beyond the schema. At 100% coverage, a baseline of 3 is appropriate; the description adds little incremental parameter clarity.

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 opens with a specific verb and resource: 'Find members of the U.S. House or Senate who have disclosed stock trades, by full or partial name.' It clearly states the tool's function and explicitly distinguishes it from siblings by noting it returns member_id used by get_member and list_transactions, and pointing to congress_leaderboard for ranking. This leaves no ambiguity about what the tool does or how it differs from related tools.

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 gives explicit when-to-use guidance: 'Start here whenever a question names a person' and explains the output feeds other tools. It also states when NOT to use it: 'To rank all members rather than look one up, use congress_leaderboard.' This directly addresses both positive and negative usage cases, which is exemplary.

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