list_capabilities

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

The readOnlyHint annotation already declares safety, and the description reinforces it with 'Read-only.' Beyond annotations, it adds meaningful behavioral context: absent capabilities are refused, so the tool also enumerates what is NOT possible. This goes beyond the structured metadata and helps an agent understand the tool's authority boundary.

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 compact and front-loaded, placing the primary action and scope in the first sentence. The second sentence adds a valuable consequence (refusal of absent capabilities). The final 'Read-only' is somewhat redundant with the annotation, but it is brief and not harmful.

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 read-only listing tool with an output schema, the description covers the core behavior, scope, and refusal semantics. The main gap is the lack of parameter semantics, but since both parameters are optional and the output schema exists, the overall context is still adequate.

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%, and the description does not explain the 'tier' or 'resource' parameters, which appear to act as filters for the capability table. The phrase 'at which tier' hints at the notion of tiers but does not connect it to the input parameters. The description fails to compensate for the undocumented schema.

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 ('Show') with a concrete resource ('the capability table') and defines its scope: every resource, operation, and field the mutate tool may touch, plus the tier. It clearly distinguishes itself from mutation tools like 'mutate' and from capability-explanation tools by framing itself as the authoritative allow-list.

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 makes the use case evident: consult this tool to learn what is possible and what is refused. 'Anything absent from this table is refused' gives strong contextual guidance for when to call it. It does not explicitly name alternatives or state when not to use it, but the purpose is clear enough.

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