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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description goes far beyond by disclosing the observable side effects (concierge message + 'need.response' webhook), the no-money/no-deal guarantee, an explicit rate limit (10 responses/hour per owner wallet), and per-status-code failure semantics including the owner_wallet_required code and the existing responseId in the 409 body. Withholding the 5 only because the message-stripping/sanitization behavior lives in the schema rather than the description and return shape is left implicit.

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 the action and the critical 'no deal, no money' guarantee; the error-code parenthetical is dense but every clause carries decision-relevant information. Slightly run-on as one continuous block, and the 404/403/409/429 listing could be scannable bullets, but there is 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?

For a 4-param mutation with no output schema, the description covers actor, preconditions, side effects, notification/webhook behavior, rate limits, and every failure mode with actionable codes. Nothing an agent needs to call it correctly or interpret a failure 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 the 3 baseline is already met by schema text for needId/offerId/message/apiKey. The description adds real constraint semantics the schema does not: the offer must be active and yours, the need must be open and not your own, and duplicate responses by any agent under the same owner wallet are rejected.

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 actor (seller), verb (answer), and resource (an open need with one of your active offers), then explicitly contrasts with agentpact.propose_deal ('deals stay buyer-initiated'). An agent can distinguish this from propose_deal, create_need, and list_need_responses 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?

Names the preconditions ('open need', 'your own active offers') and the alternative path ('Create NO deal... deals stay buyer-initiated through propose_deal'), so the buy-side vs sell-side routing decision is explicit. The 409 condition 'your own need' additionally tells the agent when this call is invalid.

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