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

Annotations cover only readOnlyHint=true; the description adds the return shape (provider names plus per-provider model counts), which is beyond what the annotation or schema declares. It says nothing about pagination or rate limits, but for a simple read-only enumeration those are minor gaps.

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, front-loaded with the core action and followed by the return content and the integration hint. Every sentence carries distinct information with no redundancy.

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-required-parameter read-only listing tool with no output schema, the description covers action, return content, and usage chain adequately. The only omission is any acknowledgement of the optional filtering params, which the schema handles.

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 100%, so the baseline is 3. The description does not mention the 'feature' or 'category' filters at all and even says 'List all available', so it adds no semantic guidance beyond the schema's own parameter documentation.

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 all available model providers'), names the platform, and describes the payload ('provider names with model counts'). It also implicitly separates itself from the sibling list-models by framing providers as the input to that tool.

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?

Gives an explicit downstream use case: 'Use provider names to filter models in the list-models tool,' which tells the agent when to reach for this tool (before filtering models). It stops short of naming when not to use it or how it relates to the generation siblings.

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