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

No annotations are provided, so the description carries the burden. It discloses the pay-per-call cost, the payment-signature header requirement, and the error behavior (error data carries payment terms). This is substantial operational context beyond the schema, though it leaves out any statement about idempotency or side effects.

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?

Five focused sentences, front-loading purpose and scope, then alternatives, then payment details. Every sentence earns its place; no filler or repetition.

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 generation tool with no output schema, the description covers purpose, alternatives, output components, and the payment requirement. It could explicitly describe the response format, but the essential calling details are 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 description coverage is 100%: both query and context already have descriptions. The tool description adds no parameter-level meaning beyond what the schema provides, so it meets the baseline without going further.

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 ('Write') and resource ('positioning for one product') and enumerates the output components (tagline, value proposition, differentiation). It goes further by naming sibling alternatives, making it easily distinguishable from generate-marketing-strategy and analyze-competitors.

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 tells when to use this tool ('Use for a single positioning block') and when not to ('For a full plan with channels and timeline, use generate-marketing-strategy; For competitor research first, use analyze-competitors'). It also mentions a payment prerequisite, which is a clear usage constraint.

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