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

With no annotations, the description carries the full burden and does well: it discloses the cost profile ('Free'), the critical side-effect boundary (does not pay or execute the downstream tool), and what the response contains. It stops short of noting rate limits, auth requirements, or whether results are cached, so it is strong but not exhaustive.

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, front-loaded with the purpose and followed immediately by the constraints. Every clause — the return payload list, the free/no-execution note — adds information with no filler.

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?

An output schema exists, so the description is not obligated to explain return values, and the cost/non-execution disclosures round out the behavioral picture. The one real gap is parameter documentation, which is missing entirely and drags this below 5.

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 0% for three parameters, so the description must compensate and it does not. 'need' is intuitive, but max_price_usd (typed as a string, unusually) and max_latency_ms are left entirely unexplained — no units, format, or what happens when they are null. The mention of 'required inputs' refers to the result payload, not the inputs.

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?

The description gives a specific verb+resource: 'Find the best agent/API tool for a task,' and enumerates what the recommendation contains (endpoint, price, required inputs, example invocation, usage evidence, fallback). No sibling tools exist, so there is nothing to differentiate against, which caps this at 4 rather than 5.

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?

'Free; does not pay or execute the downstream tool' implies a discovery-before-execution workflow, which is useful context. However, it never states explicitly when to reach for this tool versus just calling an endpoint directly, and no alternatives or exclusions are named, leaving usage implied rather than instructed.

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