List Capabilities

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

No annotations are provided, so the description carries the safety burden; it does so by explicitly stating 'Read-only; no side effects.' It also clarifies the semantic meaning of capability. It does not discuss authorization or list-size/pagination behavior, so it is not a 5.

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 short sentences, each earning its place: the core purpose/definition, a read-only safety note, and usage/alternative routing. The information is front-loaded and there is no filler.

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 simple enumeration tool with an output schema, the purpose and safety profile are covered. However, a required parameter (server_version) is undocumented in both schema and description, which creates a real calling gap; the agent does not know what value to supply or why it is required.

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 only 50%: server_version has no schema description, and the tool description does not explain it either. The description only paraphrases model_id as 'for a model,' adding no new parameter-level meaning, and leaves the required server_version parameter ambiguous.

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 states a specific action ('List every capability') on a specific resource ('for a model'), defines the term capability, and differentiates itself from get_capability ('every' vs 'one capability's full detail'). An agent can immediately understand what the tool does and how it relates to siblings.

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 says 'Use this to enumerate a model's capabilities (e.g. before reviewing functional objectives)' and names the alternative for a single capability: 'use get_capability instead.' This gives both a when-to-use context and an explicit exclusion/alternative.

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