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

Annotations give only idempotentHint=false, but the description adds substantial behavioral detail: each success increments reminder_count, a second call within REMINDER_DELAY_HOURS yields 429, REMINDERS_ENABLED does not apply, and Authorization is required. This goes well beyond the structured fields and makes side effects and rate limits explicit.

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 dense but every sentence earns its place: purpose, endpoint, policy context, exception, idempotency warning, and auth requirement. The key action is front-loaded, and no filler or repetition exists.

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 state-changing tool with side effects and rate limiting, the description covers all operational essentials: when it applies, when it refuses, what side effects occur, error behavior, and authentication. An output schema is present, so return-value details are not required in the description.

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 0% parameter descriptions, so the description must compensate. It does: document_id and recipient_id appear in the endpoint path, making their roles clear, and override_send_invite is semantically explained in the sentence about send_invite=false envelopes. Slight room remains for explicitly stating that document_id is the envelope/document identifier, but the context suffices.

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 opens with the exact action: 'Send one signing reminder to a still-unsigned recipient,' specifying the verb, resource, and condition. The wrapped endpoint and reminder-specific wording clearly distinguish this from sibling tools like send_envelope or void_envelope, which involve other lifecycle actions.

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 clear when-to-use context: target recipient must still be unsigned, and it explains policy constraints such as cap, spacing, and sequential can_sign_now. It also gives explicit when-not conditions for send_invite=false envelopes. However, it does not name alternative sibling tools or contrast them directly, so the guidance stops short of full 5-level routing.

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