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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds real value beyond them: it discloses which knowledge is filtered out (expired, retired, superseded, contradicted) and describes the lookup as deterministic, which tells the agent results are stable and quality-gated.

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?

Two compact sentences, front-loaded with the retrieval scope, no filler. Every clause carries either a filter, a cap, or a workflow instruction.

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 no output schema, the description gives the result count and the exclusion rules but never characterizes what a 'reusable answer' contains or how it is adapted. For a lookup tool this is adequate but leaves the caller guessing about result shape and the question input.

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 coverage is only 33% (only projectId is documented), so the description must compensate. The phrase 'up to 20' loosely maps to the limit maximum and default behavior, but the 'question' parameter's format and semantics are never explained, leaving half the parameter surface undocumented in both places.

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 (find) and resource (reusable answers) with precise qualifiers: 'current, explicitly approved and scope-compatible', capped at 20. That distinguishes it from generic library tools, but it does not name or contrast any sibling such as reuse_library_entry or knowledge_assets, so an agent must infer the boundary.

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 trailing clause 'adapt each result to the current requirement before separate review' implies a downstream workflow (this tool only suggests; it does not commit), which is useful context. However there is no explicit when-to-use vs alternatives guidance and no exclusion criteria pointing to a different sibling tool.

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