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

Annotations only supply destructiveHint=true; the description adds real context on top of that, flagging the mutation ('MUTATES Sendbird data') and, importantly, the partial-update semantics ('Only provided fields change'), which tells the agent unspecified fields are left intact. It stops short of saying what permissions or side effects apply, or that issuing a token has consequences for existing sessions.

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?

Three short, front-loaded sentences: the mutation warning comes first, then the partial-update rule, then the API mapping. Nothing is redundant and no sentence could be dropped without losing information.

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 four-parameter mutation with no output schema, the description covers the essentials: it mutates, it is partial, and it maps to a known endpoint. Minor gaps remain around authorization requirements and the effect of issue_access_token on existing tokens, but the operation is callable as documented.

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 all four parameters are already documented in the schema, and the description adds only the global 'only provided fields change' rule rather than per-parameter meaning. Baseline 3 applies when the schema carries the load.

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?

States a precise verb+resource ('partially updates a user's profile') and even names the underlying endpoint (PUT /users/{user_id}), which pins down exactly which operation this is. It does not explicitly contrast itself with siblings such as sendbird_create_user or sendbird_get_user, but the verb makes the distinction obvious.

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?

Usage is only implied: 'partially updates' signals this is the tool for modifying an existing user rather than creating one, and 'only provided fields change' hints at the patch-style call. There is no explicit when-to-use statement, no mention of when to prefer create_user/get_user, and no prerequisites or exclusions.

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