stats

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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond that: it is an aggregate reporting operation, scoped to all or one collection, and lists what the stats include. No unexpected side effects or hidden mutation behavior are implied.

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 two tight sentences: the first gives scope, behavior, and outputs; the second gives the canonical use case. There is no filler, repetition, or unnecessary detail.

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 is simple (one optional parameter), read-only, and has an output schema, the description is complete enough for an agent to select and invoke it correctly. It covers the scoping behavior, the metrics, and the intended question type; no additional context is missing.

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 input schema only describes 'collection' as string/null with a default of null and provides no property description. The description compensates by supplying the essential semantics: omit it to get stats across all collections, or name one to restrict to a single collection. It leaves out name-format details, but for a single optional string parameter this is sufficient.

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 uses a specific verb ('reports') and resource ('usage stats across all collections'), lists concrete outputs (point counts, document counts, disk size, distribution by source type), and notes the optional single-collection scope. This clearly differentiates it from sibling tools like collection_list or collection_info, which are about listing or inspecting collections rather than aggregating usage.

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 a clear, actionable use case: answer 'how much do I have in my RAG' style questions. It also clarifies the all-versus-one-collection behavior for the optional parameter. However, it does not explicitly mention when not to use it or name alternative tools for related needs.

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