coverage

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

With no annotations, the description must carry the behavioral burden. It usefully discloses a side effect (uncovered items become unknowns) and that options are added automatically, but it omits permissions, idempotency, whether existing unknowns are updated vs created, and other mutation semantics.

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 short sentences keep it front-loaded and efficient. The parenthetical 'options are added automatically' is somewhat cryptic but not verbose.

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?

An output schema reduces the need to describe return values, but for a tool with a mutation side effect and no annotations, the description is still incomplete: the 'feature' parameter is undefined, null inventory behavior is unexplained, and the side effect is only partially described.

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?

Schema description coverage is 0%, so the description should explain both parameters. It clarifies the inventory shape as {item: [patterns]}, but never defines the required 'feature' parameter or explains what a null inventory means.

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 conveys that this tool computes coverage of a feature inventory using probes and rule checks, and that uncovered items become unknowns. However, it is phrased as a noun phrase rather than a clear verb+resource, and it overlaps conceptually with siblings like check_rules and list_feature_unknowns without explicitly differentiating itself.

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?

It offers no explicit when-to-use or when-not-to-use guidance and does not name alternatives. The note that uncovered items become unknowns describes an outcome, not a selection criterion.

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