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

Annotations declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is fully covered. The description adds the blended-price weighting explanation, which is genuinely useful domain context, but says nothing about result caching, freshness, or truncation when limit caps at 25.

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?

Three tight sentences, front-loaded with purpose and ranking, then filters, then the blended-price rationale. No filler, though the final sentence could be folded in.

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 read-only 6-param tool with full schema coverage and no output schema, the description covers purpose, ranking semantics, and filters adequately. It lacks guidance on interpreting the ranked results or default result count behavior, but nothing an agent needs to invoke it 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 description coverage is 100%, so all six parameters are already documented in the schema. The description's mention of 'blended price weights input three to one over output' adds the meaning behind the blended sort value, which the schema does not, but otherwise it only restates the filter set.

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 ('cheapest models ... ranked by price') and immediately names the filtering axes. An agent can tell this is a discovery/ranking tool for LLM pricing 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?

Implies usage by describing the constraints you can filter on, but never states when to use this over the sibling llm_price_lookup or llm_cost_estimate, nor any exclusions. Usage is inferable but not routed.

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