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

Annotations are all false, so the description carries the burden of behavioral disclosure. It discloses billing behavior ('Billed as one verify; the first 5 each month are free') and the return outcome set, which is useful. However, it does not explicitly state whether the operation is non-mutating (readOnlyHint is false, but 'Check' implies no mutation) or describe error conditions, rate limits, or side effects. It adds some value but lacks completeness.

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 a single sentence that packs a lot of information: purpose, checks, return values, input requirements, and billing. It is front-loaded with the core purpose ('Check a filled form') followed by specifics. While dense, it is not verbose and every clause adds value. The structure is logical: purpose, checks, returns, input, billing.

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?

The tool has 3 parameters and an output schema (not shown but implied). The description explains the input (form_id + PDF) and output statuses, and adds billing context. It does not describe the output schema structure, but that is covered by the output schema itself. It lacks details on error handling or edge cases, but for a verification tool this is fairly complete.

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 schema has no descriptions for parameters (coverage 0%), but the description compensates by explaining how to provide the PDF: 'pdf_url: public https link, or pdf_base64' and that form_id is required. This clarifies the two optional PDF inputs and the required form identifier. It does not mention what happens if both pdf_url and pdf_base64 are provided, but it provides sufficient semantics for basic usage.

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 states a specific verb ('Check') and resource ('a filled form'), enumerates the exact checks performed (required fields, allowed options, consistent choices, text that fits, empty signature boxes), and lists the return statuses (complete, review required, incomplete, failed). This clearly distinguishes it from siblings like fill_form (which creates a filled form) and read_form (which extracts data) without needing to open their schemas.

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 explains how to call the tool ('Give a form_id and the filled PDF') but does not explicitly state when to use it over alternatives. The purpose implies usage (when you need to validate a completed form), and the billing note ('Billed as one verify; the first 5 each month are free') gives cost context, but there are no explicit when/when-not conditions or references to sibling tools.

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