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

Annotations already declare destructiveHint=true and readOnlyHint=false; the description adds genuinely useful behavioral context beyond them — the proposal is permanently closed, cannot be reopened, and the counterparty must send a new one. It does not mention auth requirements or rate limits, but the irreversibility disclosure is the key trait for this mutation.

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 sentences with zero filler: trigger first, consequence second, safety directive last. Every sentence earns its place.

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 one-parameter destructive mutation with an output schema present, the description covers trigger, irreversibility, and confirmation, which is nearly everything an agent needs. Return-value behavior is correctly left to the output schema.

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?

Only one parameter (proposal_id) and schema description coverage is 100%, so the schema already carries the semantic load. The description adds no format or sourcing detail about the identifier, so baseline 3 applies.

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 ('turn down a trade proposal they received') and clarifies the actor relationship by noting the proposal was received, which separates it from create/counter actions. It never names a sibling such as withdraw_proposal or accept_proposal, so differentiation is implied rather than explicit.

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?

Gives a clear trigger ('when the user decides to turn down a trade proposal') and a precondition ('Confirm with the user first'). No exclusions or named alternatives (e.g., counter_proposal as the softer option) are offered, so it stops short of full routing guidance.

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