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

No annotations exist, so the description carries the full burden. It discloses the tool's content coverage (plan features, costs, buy link) and one behavioral policy (hosted images when payments stop), but does not mention response format, whether output is a table/link, or pricing units. Adequate with notable gaps.

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 sentences with zero waste: the first sentence states output content, the second gives concrete trigger examples. The most actionable usage guidance is front-loaded after a crisp subject line, and every clause earns its place.

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 zero-parameter tool with no output schema, the description covers the returned content and the exact question types that invoke it, which is the substantive burden. Minor gaps such as response format and whether prices have recurring subscriptions are low-stakes given the tool's simplicity.

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 has zero parameters, and schema description coverage is 100% because the schema is empty. The description adds value by naming the resource the call retrieves, which is the relevant semantic contribution for a no-parameter tool; this matches the 0-param 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 explicitly states the resource (SignatureForever plans) and content (what each plan includes, costs, buy link, and credit-line removal pricing). It distinguishes cleanly from siblings: check_email_signature, create_email_signature, email_client_compatibility_matrix, and list_signature_templates are all about signature mechanics, not pricing, so an agent can differentiate 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?

The description provides explicit 'Use it when...' triggers with three concrete user questions (credit-line removal cost, signature count, hosted-image behavior on nonpayment). It lacks when-not-to-use guidance and does not name alternatives, but the siblings are so different in domain that the omission is minor.

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