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

With no annotations, the description carries the full burden, and it delivers: it discloses the state transition, side effects (clears closed_at/close_note), scoping via x-temsor-pbx-key, rate limiting (≤60/hour/key → 429), and cost (Idle $0). This is strong behavioral disclosure for a mutating endpoint.

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?

The description is compact and front-loaded with the primary purpose, then packs endpoint, state rule, side effects, auth scoping, rate limit, and cost into a few dense lines. Every sentence adds operational value with no filler.

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 single-parameter mutation with no output schema, the description covers the essential operational context: purpose, preconditions, side effects, auth, rate limiting, and cost. It does not describe response bodies or non-429 error cases, but those are less critical for selecting and invoking this tool 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?

The input schema already documents promise_id with a description covering the same 'Undo a kept|broken close — restore open' semantics, so schema coverage is 100%. The description adds no new parameter meaning beyond the schema, which matches the baseline of 3.

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?

The description states a specific action ('Undo a kept/broken close — restore an open promise') on a specific resource, and makes the inverse relationship to pbx_promises_close immediately clear. It also includes the exact endpoint and the transition condition, leaving no ambiguity about what the tool does.

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 explicitly states the precondition 'Only kept|broken → open', which tells an agent when the operation is valid. It implies when to use it (reverse a mis-click after a close) without naming pbx_promises_close as an alternative, but the usage context is clear enough.

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