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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds the genuinely useful constraint 'metadata only, no file download', which prevents an agent from expecting file content, plus the underlying endpoint mapping. It stops short of noting pagination, ordering, or behavior for an invalid/nonexistent id.

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 short sentences with the scope and the key behavioral constraint front-loaded; nothing is padded. The trailing endpoint string is marginally redundant but useful for API mapping.

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 tool this is mostly adequate, but with no output schema the description is the only place to signal what 'metadata' actually contains (field names, counts, ordering) or whether results are paginated. That gap is left open.

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?

Only one parameter and schema coverage is 100%, with the schema itself directing the agent to stiply_list_sign_requests as the source for the id. The description adds nothing about the identifier beyond the schema, 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?

States a specific verb ('List') and resource ('documents attached to a sign request'), which unambiguously separates it from sibling listing tools like stiply_list_sign_requests or stiply_list_signers. The resource scope is precise, though it never explicitly names which sibling to use instead for adjacent needs.

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?

Usage is only implied by the resource relationship — an agent can infer this is the sub-resource listing for a known sign_request_id. There is no explicit when-to-use/when-not guidance and no mention of alternatives (e.g., get_sign_request may already return document info).

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