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

Annotations already declare readOnly=false, idempotent=false, destructive=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it returns contextual guidance, current permitted actions, and a new session id, and states no customer-profile selection is needed. It does not mention auth requirements or rate limits, keeping it just short of a 5.

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?

Four sentences, front-loaded with the core purpose, then the return shape, then the routing rule. Efficient overall, though describing the return payload is somewhat redundant given an output schema exists, so it slightly exceeds the minimum needed.

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, nested-object tool with full schema coverage, complete annotations, and an output schema, the description supplies purpose, return summary, a precondition, and the alternative flow. It is essentially complete; only deeper operational details (auth/limits) are absent, which is acceptable here.

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% with 4 well-documented parameters, so the schema already carries the parameter meaning. The description only adds the 'no customer-profile selection' constraint, which is marginal beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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+resource ('Start a price negotiation with a vendor') and explicitly separates itself from a named sibling by instructing the agent to skip it and pass session.id to haggl_submit_offer when REST init already returned a session. An agent can distinguish this from the other negotiation siblings without opening schemas.

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 an explicit when-not condition ('Skip this tool if REST initialization already returned a session') and the concrete alternative action (pass session.id directly to haggl_submit_offer). It also clarifies a precondition ('No customer-profile selection is required'), leaving little to inference.

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