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

Annotations already declare readOnly/idempotent/non-destructive behavior; the description adds that the output matches the named tool's cited envelope (same rows, citations, as_of), which is valuable. No contradiction with annotations.

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?

Three well-organized sentences load purpose, parameter semantics, and return behavior without fluff. Front-loaded with the core purpose and supported by a concrete example.

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 generic tool with two parameters, an output schema present, and rich annotations, the description covers purpose, dispatch semantics, parameter format, prerequisite discovery, and output equivalence. No significant gaps.

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%, but the description thoroughly explains both parameters: capability accepts either a capability id or a query primitive name, and params is the same flat JSON object the named query tool accepts. A concrete example and the describe_capability_v1 prerequisite are provided.

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?

Clearly identifies 'Query any served capability by name' and frames itself as the generic twin of the named query tools, reaching capabilities not in the cached tool list. This distinguishes it from the many sibling query_* tools.

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?

States it is the generic twin of the named query tools and can target any capability, including ones newer than the client's cached list, implying use when no named tool exists or the list is stale. It explicitly recommends calling describe_capability_v1 first for valid filters, but does not formally state when not to use it.

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