get_user_by_id

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states it 'fetches' information but doesn't clarify what happens if the ID doesn't exist, what permissions are required, what data is returned, or any rate limits. The description is minimal and lacks important operational context.

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 extremely concise at just 6 words, front-loading the essential information with zero wasted words. It efficiently communicates the core purpose without unnecessary elaboration.

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 user lookup tool with no annotations and no output schema, the description is insufficient. It doesn't explain what user information is returned, error handling, authentication requirements, or how this differs from sibling user tools. The minimal description leaves too many operational questions unanswered.

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 100%, so the schema already fully documents the single 'id' parameter. The description adds no additional parameter semantics beyond what's in the schema - it doesn't explain ID format constraints, valid ranges, or relationship to other identifiers.

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 ('Fetch user information') and resource ('by their numeric ID'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from its sibling 'get_user_by_username' which serves a similar purpose but uses a different identifier type.

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 like 'get_user_by_username' or 'get_current_user'. It doesn't mention prerequisites, error conditions, or any context for choosing between user lookup methods.

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