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

With no annotations, the description carries the full burden; it does disclose the payload contents (pricing, specs, provider, links), which compensates for the absent output schema, and 'Get' makes the read-only nature clear. It says nothing about behavior for unknown ids, aliases that match multiple entries, or rate limits.

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 waste, with the identification method front-loaded before the returned fields. Every clause earns its place.

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 single-parameter lookup with no output schema, describing both the input convention and the returned fields is close to sufficient. The only gap is what happens on a failed or ambiguous lookup, which matters little for a simple read.

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% and the id property already documents both listing ids and aliases with an example, so the schema does the heavy lifting. The description adds the notion of 'common alias' with short examples ('claude', 'gpt', 'gemini'), a marginal addition over the schema text.

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: fetch full details for a single directory entry by id or alias. The scope word 'one' implicitly separates it from list/search siblings, though no sibling is named explicitly.

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?

Usage is implied by the id/alias input, so an agent can infer this is the detail lookup after a search. However, it never says to use search_ai_models first to obtain an id, nor does it exclude compare_ai_models or can_i_run_model.

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