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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the data source (Pinterest's own RSS feed), the 25-pin ceiling, the no-login/public-only constraint, and a detailed payment model: $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls not charged. That cost/auth behavior is exactly the kind of context annotations cannot convey.

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 tight sentences, front-loaded with the resource and its source, followed by return contents, limitations, and pricing in a logical order. No filler or repetition of the title.

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?

An output schema exists, so return-value explanation is optional, yet the description still sketches the payload. Combined with source, auth-free/public-only scope, exclusions, and per-call pricing, an agent has everything needed to decide and call correctly.

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 both username and limit are already documented in the schema. The description reinforces the public-profile constraint and the 25-pin cap but adds no format or syntax detail beyond the schema, so the baseline 3 applies.

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 ('Latest pins of a public Pinterest profile from Pinterest's own RSS feed') and enumerates the returned fields (profile name/description, pin URL/ID, text, image URL, publish date). This is clearly distinguishable from sibling social tools such as social_instagram or social_tiktok without opening any schema.

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 states applicability ('works for public profiles without login') and hard exclusions ('boards, search and engagement counts are not part of the feed'), which steers an agent away from expecting those capabilities. It stops short of naming an alternative sibling tool for those excluded use cases, so it is not a full 5.

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