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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds context beyond that: the result is a 'complete bounded' inventory (hinting at an enumeration without pagination ambiguity) and imposes a describe-before-invoke protocol that governs downstream behavior.

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 sentences, no filler. The result and scope come first, usage conditions follow, and the workflow instruction is last. Every clause earns its place.

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 enumeration tool with no output schema, the description covers what it returns, when to call it, and the required next step. It stops short of describing the shape of the inventory (e.g., that ids feed capability_describe) or any size limits, but nothing essential to calling it 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?

Zero parameters, so there is nothing to document and no schema gap to compensate for. Baseline 4 applies; the description correctly implies no filtering or scoping input is accepted.

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?

States a specific verb and resource: 'Return the complete bounded capability inventory.' The scope qualifier ('complete bounded') signals a full enumeration rather than a filtered lookup, which distinguishes it from capability_search. It does not contrast with capability_query, but the core purpose is unambiguous.

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?

Explicitly names the trigger conditions ('when the task is broad, uncertain') and the fallback condition ('or capability_search does not find the right words'), routing the agent away from the sibling that would otherwise be chosen first. It also prescribes the follow-up workflow: call capability_describe with one exact id before invoking.

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