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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds that the result is a URL, explains the terminal state requirement, and mentions a potential error response (409) for pending requests. No contradiction with 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?

Two sentences that front-load the primary purpose and then add conditions. Every sentence serves a purpose 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?

With one parameter, strong annotations, and no output schema, the description covers all necessary context: what it returns, preconditions (terminal state), and fallback behavior (setup instructions). No gaps.

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 has 100% coverage with a description for signatureRequestId. The description adds essential context: that the ID must belong to a request in a terminal state, and that pending requests return a 409 error. This goes beyond the schema's format and type info.

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?

Description explicitly states it returns the authenticated download URL for a Certificate of Completion PDF, an audit trail. This clearly distinguishes it from sibling tools (e.g., list_signature_requests, verify_pdf_signature) which serve different purposes.

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?

Description notes the tool is only available after the request reaches a terminal state and that without a key it returns setup instructions. While it doesn't explicitly list when not to use, the terminal state constraint provides clear guidance, and sibling tools do not overlap.

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