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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds a genuinely non-obvious behavioral fact beyond the annotations — the password is returned only once and is unrecoverable afterward — which is exactly the kind of disclosure that prevents agent misuse. It omits any note that repeat calls create duplicate keys.

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?

Two short sentences, zero filler, with the effect of the call front-loaded before the storage warning. Nothing to trim.

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?

The lack of an output schema is mostly compensated by explaining the one-time password return. But with no annotations covering inputs and 0% schema coverage on two required parameters, the description leaves the agent_id semantics and duplicate-creation behavior unexplained.

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 0%, so the description carries the full burden, yet it only hints at `name` ('named PBX key') and says nothing at all about `agent_id` — the more consequential parameter, whose accepted format and scope are entirely undocumented.

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 (create a PBX key) plus a meaningful qualifier, 'independently revocable named'. It is distinguishable from sibling list_pbx_keys/revoke_pbx_key/rotate_pbx_key, though the description never explicitly names those alternatives.

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 phrase 'independently revocable' implicitly hints at when to use this versus rotate_pbx_key or revoke_pbx_key, but there is no explicit when-to-use, when-not, or prerequisite guidance (e.g. that agent_id must reference an existing agent).

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