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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds that results are paginated account users and enumerates the fields returned, plus the underlying GET /users endpoint, but says nothing about pagination depth or the non-honored per_page, which the schema carries instead.

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 sentences, front-loaded with what is listed and what it returns. The filter sentence and the trailing 'GET /users' partially duplicate the schema, but no sentence is wasted at any real length.

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 usefully enumerates the returned fields (name, email, login, type, permissions, numbers), and all seven filter/paging parameters are documented in the schema. Combined with annotations covering the read-only profile, an agent has what it needs to call this 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 100%, so every parameter including page, per_page and first_name/last_name is already documented. The description only restates a subset of filter fields ('name, email, login or type'), adding no syntax or behavior beyond the schema, so baseline 3 applies.

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 specific verb and resource ('List the web users of the account') and enumerates the returned fields, which distinguishes it implicitly from placetel_list_sip_users by scoping to 'web users' including main account and sub-users. It never names the SIP-user sibling explicitly, so the differentiation is inferential rather than stated.

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 filter sentence ('Filter by name, email, login or type') implies how to narrow results, and the 'web users' framing hints at the SIP-user alternative, but there is no explicit when-to-use/when-not guidance or named alternative. An agent must infer the choice between list_users and list_sip_users.

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