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

Annotations already declare this a non-destructive write with openWorldHint and idempotentHint; the description adds substantially more: it charges nothing, requires the owner role, is asynchronous (carrier review of a day or two, display within 72 hours), and explicitly warns not to claim the name is already live from this result. That last warning is exactly the kind of behavioral caveat annotations cannot convey.

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-loads the core action and keeps every clause informational — cost, permissions, constraints, timeline, geography. It is dense and somewhat run-on in the middle (validation rules, timeline, and geography packed into single sentences), but no sentence is wasted.

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 not be described. Combined with the coverage of eligibility, cost, validation, geography, and async timing, an agent has everything needed to call this correctly and set expectations afterward.

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 50% (business_id is undocumented in the schema), and the description compensates by fully specifying the display_name rules — max 15 characters, must start with a letter, allowed character set, plus a suggestion source. business_id is only implied by context, but its meaning is unambiguous.

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 precise verb and resource: filing the caller ID name landlines display on outbound calls. It is immediately distinguishable from siblings like get_text_registration (read) and save_text_registration_details (registration details), and it names the exact artifact being changed.

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 real preconditions: included only with the business's own text registration once paid, business owner only, US local numbers only, and points to get_text_registration for the suggested name. It stops short of stating explicit when-not-to-use cases (e.g. what to do if the profile isn't approved yet).

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