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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's key contribution is the reassurance 'Nothing is charged', which resolves the real risk of a quote/refresh call. It also implies why idempotentHint=false: a refresh produces a new quote. It does not explain rate limits or whether old quotes are invalidated.

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 short clauses with the most important fact ('Nothing is charged') front-loaded, then each mode stated once. Every sentence carries information; nothing is repeated from the schema.

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 3-optional-parameter tool with no output schema, it covers both modes, the cost question, and the expiry scenario. It does not describe the shape of the quote returned for the project_id branch (fields, expiry window), a small remaining gap.

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 the baseline is 3; the description adds the default behavior for quantity ('the project's') and the expiry rationale for project_id, which is meaning beyond the schema text. All three parameters are covered, with only the uuid format left to 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?

The description names a specific verb+resource and splits the tool's two modes cleanly: read an existing quote by quote_id, or mint a fresh quote for a draft project by project_id. An agent can predict both outcomes without opening the schema. It stops short of naming a sibling, but no sibling tool overlaps enough to require it.

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?

It states the selection rule between the two modes explicitly ('With quote_id: ... With project_id: ...') and gives a concrete triggering scenario ('after the previous one expired'), plus the option to change quantity. It does not say when to prefer this over get_project or get_options, which keeps it from a 5.

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