library_stats

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well-covered. The description adds context about what is inspected (health, usage, cache counters, embedding config), which is useful, but it does not disclose details like whether the operation may be slow or trigger background refresh, which could be relevant for a stats tool.

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 a single sentence, front-loaded with the key verb 'Inspect' and lists the key data categories. Every word earns its place, with no fluff or redundancy.

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 the tool's low complexity (only one optional parameter, no output schema), the description is sufficiently complete: it names the key inspection areas. The lack of an output schema means the agent might not know the return format, but that is not required when no output schema is provided.

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?

The schema provides 100% coverage for the single parameter 'collection', describing it as an optional namespace. The description does not add any additional meaning beyond what the schema provides; thus the baseline score of 3 is appropriate.

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 inspects library tier health, usage, cache hit/miss counters, and embedding configuration, which is specific enough to distinguish it from siblings like library_shelve and library_consult. It doesn't explicitly mention the optional 'collection' parameter in the description, but the purpose is clear.

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 implies a read-only inspection tool, but does not provide explicit guidance on when to use this tool versus alternatives like library_desk_get or library_desk_status. There is no explicit mention of when not to use it or which sibling tools to prefer for other tasks.

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