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

With no annotations, the description carries full burden. It discloses key side effects: 'On accept, USDC settles on Base via the shared signer (simulated in DEMO_MODE)' and the auth requirement 'Requires X-Agent-Did header.' It also notes the autonomous nature. Missing details on non-accept actions, but it covers the most critical behaviors.

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 concise sentences that front-load the purpose, then usage, then key details. No fluff or repetition. Every sentence adds value.

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 tool with 8 parameters, no output schema, and no annotations, this description covers the main flow: opening/continuing, kinds, settlement, auth. But it omits the response format, effects of specific kinds like reject, and fuller parameter semantics. It is adequate but not fully complete.

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 low (38%). The description adds meaning for 'kind' by explaining propose|counter|accept|reject and clarifies the relationship between negotiationId and toAgentDid. However, it does not elaborate on itemIds, message, currency, or priceCents beyond schema constraints, so compensation is partial.

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?

Description states a specific verb+resource: 'Two agents negotiate a spend without a human in the loop.' It clearly distinguishes from siblings like greet or requestMerge, which serve different purposes. Title reinforces the action.

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?

Provides clear context on when to use the tool: 'Pass negotiationId to continue a thread, or omit it plus provide toAgentDid to open one.' It explains the kind actions and required header. However, it does not explicitly state when not to use or list alternatives, so it stops short of a 5.

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