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

Goes well beyond annotations: requires an API key, enumerates failure modes (conflict/not_quotable, conflict/unsupported_network), discloses the two-sided event flow (seller gets quote.requested, caller gets quote.sent), and flags echoed brief/terms as untrusted. The openWorldHint and destructiveHint=false hints are only supplemented, never contradicted.

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 purpose, then eligibility conditions, then parameters, then the reply contract — a sensible order with no filler. However, the paragraph is very dense and the closing quote_url/A2A digression runs long relative to the core action.

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 no output schema, the description defines the reply shape (quote_id, status: requested, echoed brief under _untrusted), the async seller round-trip, and the error taxonomy. For a multi-party, stateful, cross-agent tool this covers everything an agent needs to invoke it correctly.

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 80% and the description covers four of five parameters, but mostly restates schema facts ('≤ 4000 chars' duplicates maxLength). It does add flow context for budget_usdc and deadline, yet listing_id is never explained (what it is, where to obtain it) and idempotency_key is omitted entirely from the description. 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?

Opening phrase 'Commissioned work: send a brief to a listing that quotes per job' gives a specific verb (send a brief), the target resource (quote-per-job listing), and the transaction type (commissioned vs bought). This lets an agent distinguish it immediately from getQuote, sendQuote, ask, and the purchase-side siblings without opening any 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?

Explicit when-to-use ('listings with no fixed price, a quote_url, or delivery: "a2a"') and when-not ('a hosted file or a priced url/mcp listing is bought, not commissioned'), with the resulting error codes named. It also carves out a sub-case against the `ask` sibling ('ask still works on it') and points to the follow-up read via getQuote(quote_id).

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