index_status

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

No annotations are provided, so the description must carry the behavioral burden, and it does reasonably well by disclosing exactly what the report contains and how to interpret low coverage (ranking on signal agreement rather than mood). It never explicitly states the operation is read-only or side-effect-free, which leaves one gap.

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 core purpose is front-loaded in the first sentence and the rest adds diagnostic meaning. A few phrases ('gaps are visible not silent', 'worth saying out loud') are stylistic flourishes that could be trimmed, but the passage stays short.

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 an output schema exists and there are no parameters or annotations, the description supplies enough conceptual context to know what the report conveys and why it matters. It stops short of describing invocation conditions, but little else is needed for a no-arg diagnostic.

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 per the rubric the baseline is 4. There is no parameter syntax to document and the description introduces none.

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 states a specific verb and resource ('Report how much of the mood index exists') and enumerates the scope it covers (crawl coverage, labelled library layers, Claude-labelling config). This clearly separates it from all siblings, which are recommendation, retrieval, or mutation 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?

Usage is only implied: the tool exists to surface index gaps and the description notes the implication of low coverage for recommendations, which hints at when it's worth calling. But there is no explicit 'use this when...' instruction or contrast with alternatives like refresh_library.

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