capability_list

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description only adds the word 'live', hinting the catalog is dynamically generated, without saying whether it reflects runtime-registered capabilities or anything about result shape.

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, front-loaded sentences with no filler; the core purpose leads and the parameter hint follows. Slightly terse relative to what is left unexplained, but nothing is wasted.

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 two-parameter, no-required-input read tool with no output schema, the definition is minimally workable. It still leaves includeDescriptions behavior and the return shape (names only vs. full metadata) to inference, which matters for an agent choosing between this and capability_call.

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 coverage is 0%, so the description must compensate and only partly does: it explains prefix ('filter tool names') but leaves includeDescriptions completely undocumented, and it does not say whether prefix matches tool names, capability IDs, or both, nor whether it is case-sensitive.

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 — 'List the live MCP capability catalog' — which clearly distinguishes it as the read/enumeration counterpart to capability_call. It stops short of naming that sibling explicitly, but the pairing is unambiguous from the verb.

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?

'Use prefix to filter tool names' addresses how to use a parameter rather than when to choose this tool over capability_call or when a full unfiltered listing is appropriate. Usage is implied by the name/description but never stated as a condition.

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