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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the description's job is lighter. The description adds value by listing the actual fields returned (id, email, handle, avatar). No behavioral details beyond the annotations are needed, and there is no contradiction.

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?

Two efficient sentences: the first states the action and result, the second gives usage context. No unnecessary words; front-loaded with key information.

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 no output schema, the description lists the returned fields (id, email, handle, avatar). The tool is simple and has no parameters, so this covers what an agent needs to know. Complete for the given 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?

With 0 parameters, the baseline is 4. The input schema has no properties, so the description correctly adds no further parameter info. This is appropriate for a parameterless tool.

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 action 'Get the signed-in Figma user' and lists the specific fields returned (id, email, handle, avatar image URL). It also provides a use case: 'identify whose Figma account is connected.' This distinguishes it from siblings which are unrelated to user identity.

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 includes a clear usage context: 'Use to identify whose Figma account is connected.' It implicitly tells when to use this tool (when you need current user info) but does not explicitly state when not to use it or mention alternatives. Since it's a simple read with no parameters, the guidance is adequate.

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