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

Annotations show write operation (readOnlyHint=false) but description adds no behavioral traits beyond that. Does not mention rate limits, permissions, or reply behavior despite schema hints in thread_key/thread_name.

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?

Extremely concise (one sentence, 6 words), but at the cost of omitting important context. Adequate for minimal viability but not optimal.

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?

Despite having an output schema, the description does not mention return values. With 5 parameters and thread options, the description is too brief to cover the tool's complexity.

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 40%; only thread_key and thread_name have descriptions. The tool description does not explain any parameters, failing to compensate for the gap.

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?

Description states 'Sends a message to a Google Chat space' with a clear verb+resource. It distinguishes from siblings like send_gmail_message by specifying 'Google Chat space', but does not explicitly differentiate further.

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?

No guidance on when to use this tool versus alternatives (e.g., create_reaction, search_messages). No context on prerequisites, when not to use, or best practices.

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