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

With no annotations, the description carries the full disclosure burden and mostly meets it: it says the tool is free, does not execute or incur payment, and returns live price plus a ready-to-call endpoint. It adds value by describing what the result contains and implying a read-only lookup. It does not disclose auth needs, rate limits, or no-match 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?

Front-loaded with the core purpose and high-value usage context; every sentence contributes. However, the long parenthetical enumeration of all intent values duplicates the schema enum, adding redundancy that could have been trimmed or replaced.

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?

The description is strong for a tool with no output schema: it names the return fields (provider, model, live price, endpoint) and the cost-safety behavior. But the plain-language-query instruction versus enum-only schema leaves a genuine invocation ambiguity, and details like auth and no-match behavior are absent. Overall it is close but not fully complete.

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 a 3 baseline applies. The description adds the structured-routing vs semantic-matching distinction and lists valid intent values, but this conflicts with the input schema, which restricts intent to a strict enum with no free-text option — so an agent may attempt an invalid plain-language query. It also adds nothing about features, optimize_for, or max_price_usd beyond the schema.

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?

Clearly identifies a specific verb and resource: find/resolve the best AI provider for a task and return ranked, priced options. It also separates itself from execution-oriented siblings by saying it happens 'before you commit a cent' and returns a ready-to-call endpoint. This distinguishes it from aip_estimate_cost and aip_execute_with_budget enough to orient an agent.

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 description establishes the intended moment to use the tool — before committing money or executing — and states that the call is free. It also explains the two input modes: structured intent or semantic query. It does not explicitly name sibling tools to use instead in other scenarios, so it stops short of full alternative routing.

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