chat_findDmByEmail

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

Annotations already indicate readOnlyHint=true, so the agent knows this is a safe read operation. The description adds the context that it targets DM spaces and uses email lookup, which is useful but not extensive. It does not mention behavior when no DM exists or error handling.

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 clear sentence with no unnecessary words. It is front-loaded and directly states the tool's function.

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 simple read-only tool with one parameter and no output schema, the description is mostly adequate. It identifies the resource (DM space) and the lookup key (email). However, it does not specify the return format or how failures (e.g., email not found) are handled, which would be useful but not critical for such a focused tool.

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?

The input schema already provides a description for the email parameter ('Email address to look up'), and the tool description essentially repeats the same information. With 100% schema coverage, the description adds no additional semantic value beyond what the schema discloses.

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 uses a specific verb 'Finds' and resource 'Google Chat DM space', and specifies the lookup method 'by a user's email address'. This clearly distinguishes it from sibling tools like chat_findSpaceByName, which presumably looks up by name.

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 does not state when to use this tool vs alternatives, nor does it mention any exclusions or prerequisites. It merely states what the tool does, leaving usage context to be inferred.

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