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

Adds substantial context beyond the annotations: credentials survive so re-pairing is unnecessary, billing continues, the call returns before the number is actually offline, the `disconnecting` status is invisible to `get_number`, and messages are refused rather than queued. The stated idempotency and `already_disconnected` error are consistent with idempotentHint=true and destructiveHint=false, with no contradiction.

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?

Front-loaded with purpose, then consequences, then return semantics, then edge cases in a sensible order. Slightly long for a one-parameter tool, and the rationale sentence about refusing messages is a touch indulgent, but every clause conveys actionable behavior rather than 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 mutation tool with a single optional parameter and an output schema, the description covers the full picture an agent needs: reversibility, cost side effects, async completion, return shape, status visibility, message handling, and repeat-call behavior. Nothing material is left for the agent to guess.

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%, and the parameter's schema entry already explains the alias/id forms and points to `list_numbers`. The description body never mentions `number_alias`, so it adds no meaning beyond the schema. Baseline 3 applies when the schema carries the parameter documentation.

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 ("take a number offline") plus the defining constraint that distinguishes it from removal: "keeping its link to the phone" and "Nothing is deleted." It explicitly names `connect_number` as the inverse, so an agent can separate the two without opening either schema.

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?

Gives clear context for when this is the right call (deliberate temporary offline) and contrasts it with removal via the billing sentence ("billed every cycle until it is removed"), which implicitly routes to a delete/remove path. It also handles the repeat-call case. It stops short of naming a specific removal sibling tool, so the alternative is implied rather than explicit.

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