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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the read-only nature is covered. The description adds valuable context by stating it provides 'public' pricing data and explicitly disclaims checkout/account actions, which goes beyond the annotation baseline. No contradiction.

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?

The description is two sentences, succinct, and front-loaded with the primary output. Every clause contributes meaning: the first states the main return content, the second clarifies boundaries. No filler or redundancy.

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?

Despite lacking an output schema, the description enumerates the main return elements (pricing plans, rate limits, API-key location, quota guidance, recommended plan), which is reasonably comprehensive for the tool's purpose. It misses details like return format or how recommendation is computed, but the complexity is moderate and the stated scope is clear.

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 parameters are fully documented in the schema. The description adds minor context by mentioning 'requested use case' and 'quota guidance', which align with useCase and expectedRequestsPerDay, but it does not provide any syntax or meaning beyond what the schema already offers. Baseline 3 is appropriate.

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 clearly states it 'Returns public steamwebapi pricing plans, per-endpoint rate limits, API-key location, quota guidance and a recommended plan' — a specific verb+resource combination. It also explicitly differentiates from siblings by noting it does not perform checkout or account actions, and no other pricing tool exists among siblings.

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 provides clear context for when to use the tool (e.g., 'for the requested use case') and lists example use cases. It also states exclusions ('Does not perform checkout or account actions'), which guides against misuse. However, it does not explicitly name alternative tools for those excluded actions.

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