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

Annotations already flag destructive/open-world/idempotent, and the description adds real context beyond them: clearing via "", company-controlled fields returning in ignored with who changes them, mailbox propagation, quota accounting equivalent to get_signature, the held-back behavior when the month is used up, and the no-op case where nothing is written or counted.

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?

Front-loaded with the core purpose and patch rule, then quota/return behavior. It is dense and long, but nearly every clause carries actionable information (clearing, ignored fields, quota, no-op). Slightly overloaded for a single paragraph.

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 21 params, no required fields, and no output schema, the description compensates by explaining the return value (updated signature as HTML and text), the quota model, and the ignored-field feedback. Nothing an agent needs to call it correctly 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 description coverage is 100%, so baseline is 3; the description raises it by explaining the patch semantics (only send changed fields, "" clears a field) and by naming the field groups. It adds meaning beyond the schema, though individual field-level nuances are left to 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+resource and scope: "Save or change the signed-in person's own signature," then enumerates the fields it covers. The emphasis on "own" cleanly separates it from sibling update_member_field and create_signature, so an agent can route without opening schemas.

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 covers when it creates versus updates ("With nothing saved yet, this creates the signature"), the patch contract ("Give only the fields to change; the rest keep their saved values"), and the exclusion case (company brand items are set by the company owner on signatoro.com and land in ignored). That is when/when-not/alternatives in one place.

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