list_mes

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds context that this fetches the authenticated user rather than any user, which is useful since there is no parameter to specify a user. It does not add additional behavioral details like return format or auth requirements, but does not need to given the annotations.

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, front-loaded sentence: 'Fetch the authenticated user.' It is extremely concise with no irrelevant details or filler, and every word contributes to understanding the tool's purpose.

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 tool with no parameters, a read-only operation, and no output schema, the description is complete. It conveys the core behavior (fetching the authenticated user) and given the annotations, no additional context is necessary. The simplicity of the tool means the description covers all needed information.

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 tool has zero parameters, and the schema is trivially fully described. The baseline for zero parameters is 4, and the description does not need to explain parameter meanings since there are none. It correctly focuses on what the tool does.

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 'Fetch the authenticated user' uses a specific verb and resource, clearly indicating this tool returns the currently authenticated user. This distinguishes it from siblings like 'get_user' (which fetches a user by ID) and 'list_users' (which lists all users), making the purpose unambiguous.

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 guidance on when to use this tool versus alternatives. It does not mention alternatives such as 'get_user' or 'list_users', nor does it clarify contexts where this should be preferred. The usage is only implied by the name and description.

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