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

With no annotations, the description carries the behavioral burden and does well: it discloses credit cost, per-result billing, no charge on empty/failure, 24h cache semantics, and default fresh fetch. It does not detail rate limits or failure responses, but the key operational behavior is transparent.

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 short sentences, front-loaded with the core purpose; every sentence adds distinct operational info. Minor jargon ('pidgets' window) and the approximate credit figure keep it from a 5.

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?

The schema fully documents all four parameters, and the description covers costs, caching, pagination cursor, and the ~100-result window. Since there is no output schema, a one-line statement of the returned pin fields would strengthen it, but it is complete enough for correct invocation.

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. The description adds value by tying limit to cost (0.5/result) and by explaining the effective retrieval window (~100) and cache behavior, which clarifies how to set cache and limit.

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 opening phrase 'Pins from a Pinterest profile' identifies the resource and collection type, distinguishing it from sibling tools like pinterest_user_boards and pinterest_pin_details. It lacks an explicit verb, but the tool name and phrase together make the retrieval action unambiguous.

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 gives clear context—this is for a user's pins, with pagination and cache options—but never says when to prefer it over siblings such as pinterest_user_boards or pinterest_search. It implies usage but provides no explicit when/when-not guidance or alternatives.

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