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

Annotations already set readOnlyHint=true, and the description reinforces this with 'Read-only and spends no quota.' It adds auth requirements ('signatures:read' scope) and the dashboard-setup behavior without a key, plus explains status enum semantics. This goes well beyond the bare 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 front-loaded with the core action, then expands with details, usage guidance, status notes, and auth requirements. Every sentence contributes necessary information without redundancy—efficient and well-structured despite being longer than average.

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 single-parameter, read-only retrieval tool with no output schema, the description covers purpose, data richness, alternatives, status semantics, auth, and quota effects. It's fully self-contained and leaves no obvious questions unanswered.

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 coverage is 100% and the parameter description already explains where the id comes from ('Returned by create_signature_request, bulk_signature_requests, or a list call'). The tool description doesn't add additional meaning beyond what the schema provides, so baseline 3 applies.

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 uses a specific verb and resource ('Fetch one signature request by id') and immediately distinguishes itself from siblings by noting 'the detail list_signature_requests leaves out' and contrast with get_signature_certificate. It clearly defines the tool's scope and unique value.

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?

Explicitly names alternatives and when to use them: 'Use list_signature_requests to find an id and this to inspect it; use get_signature_certificate when what you actually want is the legal audit-trail PDF.' It also clarifies the 'waiting' status, preventing misinterpretation.

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