get_user_profile

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

With no annotations, the description carries the behavioral disclosure burden. It adds valuable context by explaining that an unknown ID raises a catchable ToolError rather than crashing. This goes beyond the schema and helps the agent anticipate failure handling, though it does not elaborate on other behavioral aspects.

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 two tight sentences with no filler. The primary purpose is front-loaded, and the error-handling detail earns its place as important behavioral context.

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 single-parameter read tool with an output schema, the description is complete. It states the operation, the required input, and the anticipated failure mode. Nothing essential is missing for an agent to invoke it correctly.

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 should compensate. It references the parameter by saying 'by id' and indirectly adds meaning via the error behavior for unknown IDs. However, it does not explicitly describe what user_id represents beyond the schema's property name and type.

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 states a specific verb ('Return'), a clear resource ('user profile'), and the lookup method ('by id'). This unambiguously identifies what the tool does and distinguishes it from the unrelated sibling tools.

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: call this when you need a user profile for a given ID. However, there is no explicit when-to-use or when-not-to-use guidance, and no mention of alternatives. The sibling tools are unrelated, so the lack of exclusions is not critical, but the guidance is still only implied rather than stated.

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