create_user

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

Adds substantial context beyond the annotations: non-idempotence and duplicate-effect risk (reinforcing idempotentHint=false), server-side auth injection ('never by the model'), throttling under a 30-per-10s cap with 429/5xx retries, and a full error-surface mapping (401/403/404/422). No contradiction with annotations; readOnlyHint=false, idempotentHint=false are consistent with the WRITE and 'not idempotent' statements.

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?

Front-loaded with a scannable '🟡 WRITE · creates data · POST /v2/users' header followed by clearly labeled Behavior/Parameters/Returns/Use-when sections. Slightly redundant ('creates a new user' appears alongside 'creates a record or triggers an action'), but every labeled block earns its place given the auth, throttling, and error details it conveys.

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?

Complete for a single-parameter create tool with no output schema: it covers what happens on success (created User resource), what returns look like ('HTTP <status>' plus JSON body), how errors surface, who authenticates, rate-limit behavior, and the required pre-check. Nothing an agent needs to invoke it correctly is missing.

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 baseline is 3, but the description adds a crucial caveat: the whole payload goes in the single `body` argument forwarded verbatim, and although the spec marks `body` optional, this endpoint expects one. That directly compensates for the schema reporting 0 required parameters and prevents a call with an empty body.

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?

Opens with a specific verb+resource ('Creates a new user'), the HTTP endpoint, and explicitly labels it WRITE. The dedicated 'Use when' section only-when-asked-to-create plus the related Users tools list helps an agent tell it apart from get_user/update_user/suspend_user in a large sibling set.

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?

Explicitly states when to use it ('only when the user asked to create this') and gives a concrete pre-flight procedure: verify with a 🟢 read tool that the target exists and the record isn't already there. Naming the related Users tools provides the alternative routing an agent needs.

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