Inspect PDF Digital Signatures

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, which the description complements by explicitly stating it only inspects structure and does not perform verification. There is no contradiction, and the description adds important behavioral context (no cryptographic verification) beyond what annotations provide.

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 concise and well-structured: a single sentence for purpose, followed by Args, Returns, Note, and Examples sections. Every sentence adds necessary information without redundancy, and the most critical information ('Examine digital signature fields') is front-loaded.

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 simple tool with two parameters and no output schema, the description covers all necessary aspects: purpose, input requirements, output details (including example fields), and limitations. The examples provide concrete usage scenarios, making it contextually complete for agent invocation.

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?

Input schema covers both parameters with descriptions, but the tool description adds value by explaining the file_path as 'absolute path to a local PDF file' and response_format with default and examples. The 'Returns' section and examples further clarify parameter usage, compensating for the schema's 100% coverage baseline.

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's purpose: 'Examine digital signature fields in a PDF document.' It specifies the output (total count, signed/unsigned breakdown, details per field) and distinguishes it from sibling tools like validate_tagged by focusing on structure only. The verb 'examine' and resource 'digital signature fields' are specific and 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 contexts for use ('Check if a PDF has been digitally signed', 'Inspect signer information and signing dates') and a clear limitation ('Cryptographic signature verification is not performed'). It implicitly suggests when not to use (if verification is needed) but does not name alternative tools for that purpose.

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