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

While annotations already mark readOnlyHint=true, the description adds substantial behavioral context: it is read-only and spends no quota, requires a specific API key scope, and explains error behavior (without a key, returns dashboard setup instructions). It also clarifies the nuanced 'waiting' status semantics for sequential envelopes. 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?

The description is concise yet information-dense: each sentence earns its place. It is front-loaded with the core action, then details additional fields, usage guidance, status enum explanation, and auth requirements, all in a compact, readable structure.

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 get-by-id tool, the description is complete: it covers the return fields, relationship to sibling tools, status values, auth requirements, and failure mode. No output schema exists, but the description sufficiently communicates the returned data elements, making the tool fully comprehensible.

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 schema description already explains the parameter's origin (returned by create_signature_request, bulk_signature_requests, or a list call). The description only says 'by id' without adding new meaning, so this dimension is adequately served by the schema. Baseline 3 is appropriate.

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 opens with a specific verb and resource ('Fetch one signature request by id'), clearly stating what the tool does. It distinguishes itself from siblings by enumerating the additional fields it returns (placed_fields, signed_at, etc.) and naming alternatives like list_signature_requests and get_signature_certificate, making the tool's unique role obvious.

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?

Provides explicit when-to-use guidance: 'Use list_signature_requests to find an id and this to inspect it' and 'use get_signature_certificate when what you actually want is the legal audit-trail PDF rather than the row.' Also explains the 'waiting' status meaning, preventing misinterpretation. This is a model example of usage guidance.

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