release_phone_number

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

With no annotations, the description carries the full burden. It discloses key behaviors: number returned to pool, no credit refund, message history retained. This is good transparency for a destructive action. It doesn't cover authorization or rate limits, but the core consequences are clear and help the agent understand the irreversible nature.

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 extremely concise with two sentences plus the argument note. It front-loads the purpose and consequences, with no wasted words. Every sentence adds value: action, side effects, parameter guidance.

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?

Given the output schema exists, return values are covered. The description sufficiently explains the tool's purpose, side effects, and parameter. Minor gaps: doesn't mention irreversibility explicitly (implied by 'no refund'). Overall, it's fairly complete for a single-parameter destructive 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?

The description adds significant meaning beyond the schema: 'The phone number ID to release (from list_phone_numbers)' tells the source and purpose. Schema coverage is 0%, so the description fully compensates, making the parameter clear and actionable.

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 clearly states it releases a provisioned phone number, specifying the resource (phone number) and action (release). It distinguishes from sibling tools like provision_phone_number (acquires) and update_phone_number (modifies) by detailing the consequence: number returned to pool, no refund, history retained.

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 description implies use when you want to give up a phone number, and it mentions the source of the ID (from list_phone_numbers). However, it doesn't explicitly state when not to use or compare with alternatives like update_phone_number. It provides clear context but lacks formal exclusions.

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