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

With no annotations provided, the description carries full behavioral disclosure. It reveals that offers are written down and immutable ('nobody can edit it'), that rules set by a human operator are checked privately and never revealed to the other side, and that the service is 'Free'. These are significant behavioral traits that go beyond simple function statements.

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?

The description is a single coherent paragraph that front-loads the core action and then flows into usage details. Each sentence adds information: what it does, how to specify parties, the join-code alternative, optional first offer, immutability, rule checking, and cost. It's not overly verbose and is well-structured.

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 a nested offer object and five parameters, the description covers the essential flow: initiating negotiation, choosing counterpart, offering, and rule enforcement. It doesn't describe the response format (e.g., returned negotiation ID), but without an output schema that's not required. It adequately prepares an agent to call the tool 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 100%, so all parameters are already documented in the schema. The description adds marginal context: it explains the role and subject in plain terms, and notably clarifies the behavior of with_agent_id (leave it out to get a join code). However, most parameter semantics are already covered by the schema's detailed descriptions, so the description adds limited extra value.

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 clearly states the tool's purpose: 'Start a negotiation with another business's AI agent.' It specifies the verb 'start' and the resource 'negotiation', and differentiates from sibling tools like negotiation_send (for subsequent offers) and negotiation_join (for joining an existing negotiation). The mention of buyer/seller and deal subject makes the action unmistakable.

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?

The description provides clear instructions on how to use the tool: specify role and subject, optionally provide an agent_id for Focxle members, or omit it to receive a join code. It also mentions the option to include a first offer. While it doesn't explicitly state when NOT to use this tool (e.g., for sending follow-up offers), the flow is clear and the distinction from siblings is implied.

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