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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true. The description adds genuinely new behavioral context by disclosing the real-world side effect ('each attempt rings their phone') and warning against over-use, though it says nothing about permissions or what a failed attempt looks like.

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, front-loaded sentences: purpose, when-to-use/caution, then the Args note. No padding and no repetition of the title.

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?

An output schema exists so return values need no explanation, and the description covers purpose, trigger, caution, and the one parameter's provenance. Nothing an agent needs to call this correctly is missing.

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 0% on the single parameter, but the description compensates by explaining what recipient_id means ('Recipient to re-verify') and where to obtain it ('from list_recipients'), which the bare string schema does not convey.

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+resource ('re-send the consent verification call') and scopes it to recipients who haven't confirmed. This clearly distinguishes it from siblings like test_call, add_recipient, or list_recipients.

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?

Explicitly names the trigger condition ('list_recipients shows consent as pending and the person missed the first call') and gives a when-not constraint ('don't repeat it more than necessary'), routing the agent to the sibling that supplies the ID.

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