corpus_stats

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

No annotations are provided, so the description carries the behavioral burden. It makes the read-only nature clear through 'Report what the local research corpus has accumulated' and 'has enough history behind it', strongly implying no mutation or side effects. It adds useful context about what data is summarized, though it stops short of explicitly saying the tool never modifies data.

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 tightly written sentences. The first states what the tool reports with concrete components; the second gives a practical usage scenario. No filler or repetition of the tool name.

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 zero-parameter, read-only statistics tool with an output schema available, the description covers the essential what and when. Nothing needed for correct invocation 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 tool has zero parameters and the schema coverage is 100%, so there is no parameter documentation burden. The description adds value by describing what the output reports, which is effectively the parameterless call's meaning.

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 ('Report') tied to a clear resource: the local research corpus. It enumerates exactly what the report contains (result and search counts, source-class spread, date range), which clearly distinguishes it from sibling search/read/demand tools.

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 concrete when-to-use scenario: checking whether a longitudinal question has enough accumulated history to be answerable. It does not explicitly mention exclusions or alternatives, but no alternatives are needed for a stats/summary tool.

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