Prepare signature placeholder

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

Annotations already mark this as idempotent and non-destructive. The description adds useful behavioral context beyond annotations: it explains the placeholder size customization, the page index parameter, the auto-injection behavior of sign_pdf, and the PDF/A conformance options. It does not contradict 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 a single paragraph that is efficient and front-loaded with the tool's purpose and relationship to sign_pdf. However, it could be slightly more scannable with bullet points for the three usage scenarios. No wasted sentences, but minor improvement possible.

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 12 parameters, rich input schema, and the presence of an output schema (as per context signals), the description covers the tool's optionality, key use cases, and relationship to sibling tools. It does not elaborate on return format or error handling, but the output schema fills that gap. Overall, it provides sufficient context for a complex tool.

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 description coverage is 100%, and each parameter has detailed descriptions within the schema. The tool's description itself does not add significant parameter-level details beyond what the schema already provides. Baseline of 3 is appropriate as the schema does the heavy lifting.

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 tool creates a PDF with an embedded /Sig AcroForm placeholder for digital signing. It uses a specific verb (create) and resource (PDF with signature placeholder), and distinguishes itself from the sibling sign_pdf tool by explaining when to use this tool vs. letting sign_pdf auto-inject the placeholder.

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 explicitly notes that this tool is optional and lists three specific scenarios where it should be used (customizing placeholder size for >4096-bit RSA keys, attaching widget to a specific page, or precomputing the placeholder separately). It also advises when to not use it: 'Otherwise call sign_pdf directly.' This provides clear when-to-use and when-not-to-use guidance.

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