send_message

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

With no annotations provided, the description carries the full burden of disclosing behavior. It mentions 'capture the response' but does not explain timeout behavior, error handling, or side effects. This is minimal and leaves the agent without important contextual information about how the tool behaves in edge cases.

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, clearly structured sentence that accomplishes its purpose without redundancy or extraneous content. It is front-loaded with the primary action and followed by the outcome, making it easy to parse.

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?

Given the tool's simplicity and the fact that all parameters are described in the schema, the description is mostly adequate. However, it lacks details about what happens on timeout or when expectResponse is false, and the return value is only vaguely indicated by 'capture the response'. These gaps make it less complete than ideal for a tool with no 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?

Schema coverage is 100%, so the baseline is 3. The description does not add extra meaning to the parameters beyond the schema; it only references 'message' implicitly. It fails to elaborate on timeout or expectResponse semantics, but the schema already covers those details, so the description adds no significant 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 function: sending a message via chrome.runtime.sendMessage() and capturing the response. The verb 'send' and specific API named make it distinct from sibling tools like evaluate or screenshot, which serve different purposes.

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 no explicit guidance on when to use this tool versus alternatives. It does not mention scenarios where this is preferable to content_script_eval or other communication mechanisms, nor does it list any exclusions or prerequisites.

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