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

Adds real consequences beyond the annotations: the change affects LIVE call handling immediately and callers get routed differently. This is consistent with destructiveHint=true and idempotentHint=true rather than contradicting them. It stops short of stating permission/scope requirements or what happens to the previously active profile.

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 "WRITE:" and the impact warning, then the id-discovery pointer, then the endpoint. No filler sentences.

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 2-parameter mutation with no output schema, the description covers purpose, live impact, prerequisite lookup, and the underlying endpoint. Nothing an agent needs to call 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 coverage is 100%, so baseline is 3; the description still adds value by explaining where number_id and profile_id come from (placetel_list_number_profiles) and framing profile_id as the profile to activate. It does not clarify units/formats, but the schema already does.

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?

Specific verb+resource: "switch the active routing profile of a phone number", with concrete examples (Holiday or Night). It is clearly distinct from the read-only sibling placetel_list_number_profiles, which is explicitly named as the id-lookup tool.

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?

It tells the agent exactly what to do first ("Find ids with placetel_list_number_profiles") and states the operation context (changing active routing profile). There is no explicit when-not guidance or mention of an alternative mutation path, but for this operation no competing sibling exists.

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