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

The annotations already declare openWorldHint, idempotentHint and destructiveHint=false, but the description adds genuinely new behavioral facts: the paid-credit cost per call, the required APIFY_TOKEN, the identity-gate failure mode (identity_mismatch with no counts instead of a stranger's numbers), and that counts are real integers that can be summed. The 'Read only' phrasing sits in mild tension with readOnlyHint=false, but the description immediately qualifies it by disclosing the credit spend and external actor execution, which is the actual reason the tool is not flagged read-only.

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?

Four dense sentences, front-loaded with the outcome and followed by interpretation, failure semantics, and cost/auth. The 'boards are curation effort' sentence is arguably interpretive filler for a parameter-oriented reader, but it earns its place by telling the agent how to weight the returned fields.

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 no output schema, the description carries the full burden and delivers: it enumerates the returned fields, the flat single-row shape, the caching behavior (in schema), the failure mode, the auth prerequisite, and the cost model. An agent has everything needed to call this correctly and to interpret the result.

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 coverage is 100%, so the baseline is 3, but the description adds interpretive value the schema does not: it explains why handle is more than a convenience (it skips the identity risk because Pinterest handles rarely match the domain stem) and why company_name reduces wrong matches via the identity gate. That rationale goes beyond the per-parameter text.

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 opens with a specific verb and resource pair — 'Resolve a company domain to its Pinterest business account' — and then enumerates the exact return payload (follower, following, pin, board counts, claimed website, merchant status, last pin date). There are no sibling tools, but the scope is still unmistakable from the first clause alone.

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?

It states the operating conditions clearly: domain vs. handle selects discovery vs. direct fetch, handle presence skips identity risk, and the call requires an APIFY_TOKEN and consumes credits. It does not state an explicit 'do not use this when…' case, but with no siblings to disambiguate against, the context is adequate rather than exhaustive.

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