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

Annotations only give generic flags (destructive, non-idempotent, open-world). The description adds concrete behavioral facts beyond them: a hard cap of 3 reminders per request, a minimum one-hour gap since the last signer email, the required source of request_token, and the fact that link-delivery requests have no email to resend. That is exactly the context an agent needs before invoking a rate-limited, outward-facing send.

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?

Four compact sentences, each carrying a distinct operational fact (what it does, precondition, rate limit, link-delivery caveat) with the core action front-loaded. 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 no output schema, the description still covers the essentials for a side-effecting send: precondition, token provenance, rate limit, and the edge case where resending is impossible. Nothing critical for a correct invocation is missing.

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 only 33%, but the description compensates for request_token by stating it comes from send_for_signature. The message parameter is already documented in the schema (plain text, 500 chars, links stripped). request_id remains undocumented in both places, so the description adds partial but not full meaning.

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 and resource (email the signer again with the same private signing link) and scopes it to requests with status "pending". This clearly differentiates it from the sibling send_for_signature, which performs the initial send.

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 says to use it only when the user asks, states the precondition (status "pending", waiting for the signer), and routes the agent to a different action when delivery is "link" because no email was sent. When-to-use, when-not-to-use and the alternative path are all covered.

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