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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context: it returns 'committee summaries (name, house, active status, ID)' and explicitly describes the follow-up actions, which tells the agent what to expect from the output and how to chain tools. This goes beyond the annotations without contradicting them.

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 and well-structured. The first line is a clear imperative ('USE THIS TOOL WHEN...'), immediately followed by the return summary and downstream steps. Every sentence earns its place: purpose, output, and usage flow. No fluff or repetition of schema details.

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 that an output schema exists (so return values are already structured) and annotations cover safety and idempotence, the description provides sufficient context for decision-making. It explains what the tool does, what it returns, and how to proceed with the results. It does not cover edge cases like empty results or error behavior, but these are not critical for a simple read-only search tool; the overall guidance is complete enough.

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 four parameters (house, limit, query, active_only) have detailed descriptions with defaults, bounds, and examples in the schema itself. The tool description does not add additional parameter-level meaning; it only mentions 'name, house, or active status' in the purpose, which maps to existing schema fields. Per the rubric, a baseline of 3 is appropriate when the schema does the heavy lifting.

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's purpose: 'searching or listing UK parliamentary select committees by name, house, or active status.' It names the specific resource (UK parliamentary select committees), the actions (searching/listing), and the filtering dimensions. It also distinguishes itself from sibling tools by directing the user to pass committee_id to committees_get_committee or committees_search_evidence afterward, thereby clarifying its unique role in the workflow.

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 opens with 'USE THIS TOOL WHEN searching or listing...' which is an explicit when-to-use directive. It also provides downstream usage guidance ('AFTER calling, pass committee_id into...'), which helps the agent choose the next tool. However, it does not explicitly state when NOT to use this tool or name direct alternatives for the same search task, which would elevate it to a 5.

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