send_message

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

No annotations are provided, so the description carries the full burden. It clearly conveys the mutating nature of the action ('send') and adds the thread_key reply behavior, but it does not disclose permissions, visibility of the sent message, error behavior, or any return value. This is adequate but not rich.

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 compact and front-loaded with a single purpose sentence followed by a terse Args list. Every line contributes necessary parameter meaning, and there is no filler or repetition.

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 low-complexity tool with three simple parameters and no output schema, the description provides enough information to call it correctly: purpose, all parameter semantics, and optional thread behavior. It does not mention return values or error conditions, but the operation is straightforward enough that these are not blocking gaps.

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 0%, so the description must compensate for the bare schema. It does so by explaining all three parameters: space gets a concrete 'spaces/...' example, text is identified as the message body, and thread_key is described as an optional way to reply in an existing thread. It lacks constraints such as length limits but is otherwise strong.

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 opens with 'Send a text message to a Google Chat space,' which is a specific verb plus resource. It clearly distinguishes this write-oriented tool from the read-oriented siblings list_spaces, list_messages, and search_messages.

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 intended use is implied by the verb 'send,' but the description never explicitly states when to prefer this tool over alternatives or mentions any prerequisites or exclusions. It provides enough context for a simple send operation, but stops at implied usage rather than explicit guidance.

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