Fetch a sip user

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so 'Read-only' merely restates structured data. The description adds no behavioral context such as what happens when the id does not exist, whether the resource is scoped to the caller's account, or any auth requirements.

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?

Extremely short and front-loaded with the action and resource, plus the endpoint in parentheses. There is minor waste in repeating 'Read-only' after the annotations already say so, but nothing is confusing or padded.

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 simple two-parameter read tool with full schema coverage and annotations, this is largely sufficient to invoke correctly. However, with no output schema present, the description could have said what a fetched sip user record contains, and it omits error behavior for an unknown id.

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%: the id path parameter and the response_format enum (markdown vs json) are both documented in the schema, including the default. The description contributes nothing extra about parameter meaning, so the baseline of 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 (fetch) and resource (sip user) and includes the underlying endpoint GET /sip_users/{id}, making it clearly a single-resource read. It does not explicitly distinguish itself from siblings like placetel_list_sip_users or placetel_get_user, but the singular 'a sip user' plus the {id} path implies the distinction.

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?

There is no guidance on when to use this versus placetel_list_sip_users (to discover ids) or the related placetel_update_sip_user / placetel_delete_sip_user. The only hint is the word 'Read-only', which is implied usage at best, not an explicit routing statement.

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