gmail_signature

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

No annotations are supplied, so the description carries the disclosure burden; the verb 'Read' implies non-mutation, and the '' = none note is useful behavioral context. It does not say how the value is scoped (account, device) or what happens if no mobile signature has ever been set.

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?

It is a single sentence with no padding, but the parenthetical '("" = none: the web signature is used)' is compressed into a form that is hard to parse on first read.

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?

A zero-parameter read with no output schema needs the description to explain the return value, and it only partly does: '' is explained, but the shape otherwise (the raw signature string) is left implicit.

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?

The tool takes zero parameters, which is the automatic baseline of 4; the description adds nothing parameter-wise because there is nothing to add.

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 ('Read the mobile signature Gmail adds to mail sent from the phone'), which is enough to separate it from the mutating sibling gmail_set_signature. The parenthetical about the empty string muddies an otherwise clear purpose.

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?

No statement of when to call this versus gmail_set_signature, which is the obvious alternative in the sibling list. The agent must infer that this reads and the sibling writes.

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