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

Annotations only say it is a non-readonly, non-idempotent, non-destructive call; the description adds the information that matters operationally: a check consumes one unit, full consumes three, and request_id must be preserved for retries. That credit-consumption and retry contract is not derivable from the annotations. It does not explain what the generated prompt contains or what happens if the allowance is exhausted.

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?

Four short sentences, front-loaded with the purpose before the prerequisite, the cost model and the retry rule. Every sentence carries distinct operational information with no 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 7-parameter, no-output-schema tool, the definition covers purpose, prerequisite, cost and retry semantics, which is most of what the agent needs. The remaining gap is the return shape (presumably prompt text) and what happens when the allowance is exceeded, which has no schema or annotation backing.

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 already 86%, so the baseline is 3, but the description adds real meaning by tying the 'check' and 'full' scope values to a concrete cost of one versus three units. It reinforces the request_id retry rule and frames source=domain as the saved registration, certificate, DNS and email observations, though check_id's required-for-check behavior is only in the schema.

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 uses a specific verb and resource ('Generate a fix prompt from saved domain observations') and adds a clarifying paraphrase about preparing a coding-agent prompt from an owned report. An agent can tell it produces a prompt artifact from stored domain data, though it never explicitly names the look-alike sibling generate_fix_prompt / generate_site_fix_prompt to explain the difference.

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?

It gives a concrete prerequisite ('Read prompt_allowance first') and states the allowance/plan constraint, which tells the agent the condition under which this call is valid. It stops short of explicit when-not-to-use guidance or naming the sibling tool to choose instead.

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