cache_stats

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

The description indicates a read-only operation (returning statistics) with no explicit destructive behavior. However, it lacks disclosure of potential side effects, authentication requirements, or rate limits. Since no annotations are provided, the description carries the full burden, and it only partially meets that need.

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, concise sentence that front-loads the purpose ('Return cache statistics') and lists the specific outputs. Every word is necessary and there is no 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 simplicity (no parameters, no output schema), the description is sufficiently complete. It clearly lists the three statistics returned. It could optionally mention that the tool is safe to call at any time, but this is not required for basic completeness.

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 tool has zero parameters, so the description adds no parameter-specific information. According to guidelines, baseline score is 4 when there are 0 parameters, as no compensation is needed.

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 explicitly states the tool returns cache statistics including total entries, total hits, and last cached timestamp. It uses a specific verb ('Return') and resource ('cache statistics'), and clearly distinguishes from sibling tools like 'cache_list' (which likely returns key listings) and 'cache_store' (which stores items).

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?

No guidance is provided on when to use this tool versus its siblings ('cached_fetch', 'cache_list', 'cache_store'). The description only states what it returns, leaving the agent to infer appropriate usage without explicit context or exclusions.

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