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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint false), the description discloses meaningful behavioral traits: it returns two possible kind variants, and the summary always reflects the full set even when limit truncates rows. This is exactly the kind of behavioral nuance an agent needs that structured fields alone cannot convey.

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 front-loaded and logically organized, but it repeats the return information twice ('Returns {...} or {...}' followed by 'Returns: The set of known coverage gaps...') and the final example uses a placeholder value that adds no real guidance.

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?

Since there is no output schema, the description responsibly explains both return shapes and the summary semantics, and it covers the conditional parameter rule. The main gap is the undocumented repo parameter and lack of any error/edge-case context, but overall it is sufficiently complete for a read-only enumeration tool.

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 description explains three parameters well: scope_kind's enum values, scope_id's conditional requirement, and limit's truncation behavior. However, with schema description coverage at 0%, it fails to mention the optional repo parameter at all, leaving one parameter semantically undocumented.

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 opens with the specific verb 'Enumerate' and the resource 'structural coverage gaps', then gives concrete examples ('silent tools, artifacts with no eval, un-probed tenants'). This clearly distinguishes the tool from the sibling introspection_corpus and introspection_system tools and leaves no ambiguity about what it does.

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 states the scope_kind values, makes the conditional requirement explicit ('scope_id required if scope_kind=tenant'), and explains limit vs summary behavior. It does not explicitly name sibling alternatives or say when not to use it, but the invocation context is clear enough for an agent to use it correctly.

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