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

Annotations already declare destructiveHint=true, and the description's 'MUTATES' merely restates that in words. It adds no new behavioral context beyond the annotation, such as error behavior, idempotency, permission requirements, or side effects. Since the description does not enrich the annotation, it falls short.

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 just two sentences with zero filler. The core operation is front-loaded ('MUTATES Sendbird data: creates a new user'), followed by the API endpoint. Every word earns its place, making it highly efficient for an agent to parse.

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?

With no output schema, the description does not explain what the response contains (e.g., created user object, access token when requested), nor does it address failure cases like duplicate user_id conflicts. The description plus schema and annotation are enough to make the call, but missing operational details reduce completeness for a mutation tool.

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% — all five parameters (user_id, metadata, nickname, profile_url, issue_access_token) are fully documented in the input schema. The description adds no parameter-specific meaning, so a baseline of 3 is appropriate given the schema already does the heavy lifting.

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 uses a specific verb ('creates') and resource ('a new user'), plus the exact API endpoint 'POST /users'. This clearly distinguishes it from read-only siblings like sendbird_get_user and sendbird_list_users, and from sendbird_update_user. The title and name further reinforce the intent.

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 usage is implied by the verb 'creates' — an agent can infer this is the tool for making a new user. However, there is no explicit guidance about when not to use it, what to do if the user already exists, or how it relates to sendbird_update_user as an alternative. The description provides no exclusions or conditional routing.

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