release_twilio_number

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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds value only by scoping the destruction to Twilio SMS/voice numbers and excluding WhatsApp numbers; it says nothing about irreversibility consequences, required permissions, or failure modes.

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 the action and scope, followed by the exclusion and payload guidance. No filler and every sentence carries information.

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 pass-through payload tool with no output schema and full annotation coverage, the description covers action, scope, exclusion, and typical payload fields. Minor gap: no mention of what a successful response or failure could look like, but this is a low-complexity tool.

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%, but the schema's payload description is a tautology ('Full request body object for /utils/twilio/release-number'). The description compensates by naming the typical fields (phoneNumber or phoneNumberSid), which is genuinely additive information an agent would otherwise lack.

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 ('Release (delete) a Twilio SMS/voice number from the workspace'), clarifies the parenthetical equivalence, and explicitly separates it from WhatsApp number deletion. An agent can distinguish it from import_twilio_number, check_twilio_number, and whatsapp_numbers_write without reading the 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?

The exclusion ('does not remove WhatsApp Cloud API waNumbers') gives a useful scope boundary, implying the sibling to use for WhatsApp numbers. However, it does not name that alternative tool or state prerequisites (e.g. number must be imported/active first), so guidance 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.