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

Annotations already indicate this is a mutating, non-idempotent, open-world action. The description adds meaningful behavioral context: an email is actually sent, the recipient replies directly to the user, and the agent must never invent contact details. This goes beyond the annotation flags without contradicting them.

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 sentences, each earning its place: the action and outcome, the usage condition, and the data-provenance constraint. The most important operational guidance is front-loaded, with no redundant 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 tool with 8 parameters and no output schema, the description covers the essential context: what happens, who replies, when to call, and the confirmation requirement. It does not describe error or failure behavior, but the external-reply outcome is clear and the schema covers parameter details.

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 schema already documents each parameter. The description reinforces the key semantic constraint that all fields must come from the user and that user_confirmed requires prior agreement, but it does not add substantial per-parameter meaning beyond the schema. Baseline 3 is appropriate.

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 states a specific verb ('Send'), a specific resource ('sourcing enquiry or quote request to Cambridge China Bridge'), and the delivery mechanism ('by email'). It also clarifies the expected outcome ('they reply to the user directly'), which clearly distinguishes it from the sibling research/check tools.

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 gives explicit when-to-call guidance: 'Only call this when the user has asked to contact them'. It also specifies the required precondition: show the user exactly what will be sent and get their agreement. This is direct, actionable usage guidance.

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