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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower; the description adds genuine value by disclosing the returned fields (type, context length, org, license, per-token pricing) since no output schema exists. It says nothing about pagination, result size, or how the optional dedicated filter changes the response.

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?

Front-loaded with the verb and return payload in one dense sentence. The trailing 'Together: GET /models.' is an API mapping that adds little for an agent, but it costs only a few tokens.

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?

With no output schema, the description compensates by enumerating the returned fields, which is the key completeness gap for a listing tool. Missing only secondary details like pagination or result ordering.

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?

Only one optional parameter and schema description coverage is 100%, so the schema already explains the dedicated filter fully; baseline 3 applies. The description's list of model types does not correspond to any parameter and adds no filtering syntax.

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?

Specific verb+resource ("List Together's models") plus an enumeration of the fields returned (type, context length, organization, license, pricing), so the agent knows exactly what this surface provides. It doesn't explicitly differentiate from the many other together_list_* siblings, but the resource is unambiguous on its own.

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?

No statement of when to call this versus alternatives, nor any prerequisite or sequencing guidance (e.g. 'call before chat_completion to pick a model'). The use case is only implied by the resource name.

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