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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral context: it is a 'plain mechanical read', requires no upload, spends no render quota or extraction credits, and returns a 409 error if the render is not successful. This fully discloses behavior beyond the annotations.

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 four sentences long and packs significant information without redundancy. It is front-loaded with the core action and gradually adds context. A minor improvement would be to further condense the last sentence about errors, but overall it is well-structured and efficient.

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 only two parameters (all documented) and no output schema, the description covers purpose, use cases, preconditions, return formats for both type variants, error scenarios, and quota/credit implications. It also differentiates from sibling tools. This is complete for a tool of this complexity.

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?

Although the schema already describes both parameters with 100% coverage, the description adds meaning by explaining the default for 'type' ('text'), detailing the return structure for each variant, and linking the 'fields' type to the sibling tool edit_pdf ('the latter is how you discover what edit_pdf can fill in'). This enriches the parameter understanding beyond 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 clearly states the verb ('Read') and resource ('text or the form fields back out of a document this account already rendered'), with specific variants for 'text' and 'fields'. It explicitly distinguishes itself from the sibling tool extract_document, making the purpose unambiguous.

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 provides explicit guidance on when to use this tool versus extract_document ('Choose extract_document instead when the PDF came from outside Kamy or when you need AI-structured JSON against a schema'). It also notes the prerequisite (render status must be 'success') and mentions that no quota or credits are consumed, helping the agent decide appropriately.

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