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

The description discloses that the tool sends real email and warns about rate/frequency, which is valuable behavioral context beyond the annotations. Annotations already indicate it is not read-only and not destructive, but the description adds the real-world side effect (email delivery) and the caution about repeated use. It could go further by noting whether reminders are logged or if there are limits, but the key behavioral trait is covered.

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 compact and front-loaded: it states the action first, then explains the two modes, then adds the caution. Every sentence earns its place, and there is no redundant repetition of the schema or title.

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 two-parameter tool with no output schema, the description covers the essential context: what it does, how to target signers, and the caution about real email. It could mention what happens if no signers are pending or whether the response indicates success, but the core information an agent needs to invoke it correctly is present.

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%, so the schema already documents both parameters. The description adds meaningful semantics by explaining the optional signer_email behavior (omit for all, pass for one), which clarifies the parameter's purpose beyond the schema's short description. This is a solid enhancement over the baseline.

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 clearly states the tool's function: re-sending signing invitation emails to pending signers. It distinguishes itself from siblings by focusing on the reminder action, and it explicitly explains the two modes (all pending signers vs. a specific signer), which is more specific than the title alone.

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?

The description provides explicit guidance on when to use the tool and how to choose between the two parameter modes. It also warns against repeated calls, advising once per day per signer, which is actionable usage guidance beyond what the schema provides.

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