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 covered. The description adds useful behavioral detail by disclosing what each match contains (id, rank, Index, reasoning-effort configurations), which tells the agent the call is cheap and informative. It does not mention the 25-result cap or ranking order, which are minor omissions given the schema documents limit.

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 sentences, zero filler, with the matching criteria and the return payload front-loaded before the downstream-tool pointer. Every clause carries information.

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?

There is no output schema, and the description compensates by enumerating the returned fields and their purpose, so the agent knows what it will get back. Combined with a fully documented two-parameter schema and complete annotations, nothing needed to call this correctly is missing.

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 100%, so the baseline is 3; the description earns a bump by giving concrete query examples ('opus', 'gemini 4', 'deepseek') that clarify loose fuzzy matching across names, aliases, ids and developers. It adds nothing for limit, which the schema already explains.

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 ('Find models') plus the exact match keys (name, alias, id, developer) with concrete examples. It also names the downstream siblings (get_model, compare_models), so an agent can distinguish it from a single-model lookup without opening the schema.

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?

The phrase 'for use with get_model and compare_models' implies the workflow (search first, then fetch/compare), which is clear context. It stops short of an explicit rule such as 'use this when you only know a partial name; use get_model when you have the exact id,' so no true when-not guidance.

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