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

Annotations only declare destructiveHint=true; the description goes beyond that by disclosing the default test_mode behavior (no real emails) and the consequence of test_mode=false (a REAL, legally-binding request). This is meaningful side-effect context an agent would not get from the schema alone. It stops short of describing return values or rate-limit behavior.

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 functional sentences with the high-stakes test_mode caveat front-loaded, followed by the endpoint. Nothing is padded and the most important warning is not buried.

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 need not explain returns, and 100% schema coverage handles parameters. It covers the critical trap (test_mode default) that governs whether a real legal request is sent. It could note that the returned signature_request id feeds siblings like remind/cancel, but that is a minor omission for this call-site.

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 description coverage is 100%, so every parameter already carries inline documentation and the baseline is 3. The description restates template_ids, signers and the test_mode semantics but adds no format or syntax detail beyond the schema.

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 ('Sends a signature request built from template(s) to the given signers'), and names the templates and signers involved. It is immediately distinguishable from read siblings like get_signature_request and list_templates, and from the mutation sibling remind_signature_request.

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?

Gives clear context for the key decision (test vs. real send) by stating test_mode defaults to true and must be set false for a real request. It does not, however, mention exclusions or route the agent to alternatives such as remind_signature_request or cancel_signature_request, which is a mild gap.

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