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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered and the trailing 'Read-only' is largely redundant. The description earns credit for disclosing the retrieval mechanism ('Hybrid keyword and semantic search') and that results combine messages with peer facts, which annotations do not convey.

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?

Three short sentences, front-loaded with what the tool returns, followed by the mechanism and the routing contrast. No sentence is wasted and nothing important is buried.

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?

With an output schema present, return values need no explanation, and the description covers scope, mechanism, and the primary alternative. It is only slightly incomplete in not clarifying the division of labor with the facts-oriented siblings (list_conclusions, get_peer_card).

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%, so the schema already documents query, peer_id, session_id, workspace_id, and both limits including defaults. The description's conditional 'plus (for a peer) the facts memory holds about them' hints at peer_id behavior but adds no syntax, format, or constraint detail beyond the 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?

States a specific verb and resource ('Find raw evidence: messages that match the query') and clarifies the compound result set by including peer facts. It also distinguishes itself from the chat sibling directly, so an agent can tell the two apart without opening either schema.

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?

Explicit routing guidance is given against the most confusable sibling: 'Use chat when you want an answer instead of evidence.' However, it does not address the overlap with list_conclusions/get_peer_card for the facts portion of its output, leaving one ambiguity for the agent to resolve on its own.

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