library_stats

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

No annotations are provided, so the description carries the full behavioral burden. It doesn't state whether the result is a computed aggregate, whether it is cached, what 'deep-read coverage' implies, or anything about permissions or cost beyond the bare summary phrase.

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?

A single sentence, which is appropriately sized for a zero-parameter tool. However, 'deep-read coverage per field' is jargon that only becomes meaningful with more context that the description doesn't provide.

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?

For a parameterless stats tool with no annotations and no output schema, the description needs to explain what the returned totals represent and how 'coverage per field' is computed. It doesn't, leaving the agent unable to interpret or trust the output.

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 takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 is appropriate — no parameter guidance is needed, and the description doesn't need to explain any inputs.

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 phrase 'Totals for the library plus deep-read coverage per field' is vague about what resources are counted and what 'deep-read coverage per field' means. It gestures at an aggregate/stats operation but doesn't clarify the domain (posts? tags? folders?) versus siblings like search_posts or list_tags.

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 indication of when to use this tool versus the sibling list/search tools. An agent cannot tell whether this is a summary view, a health check, or a prerequisite for other calls.

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