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

Annotations already establish a safe read-only, idempotent operation, but the description adds substantial behavioral context: results are newest first, include secret-board Pins and Pins created by other tools, and each Pin carries isRepin, creativeType, boardId, destinationUrl with UTMs, and createdAt. It also discloses the important pinType edge case, pagination behavior with cursors, and that reading Pins consumes no credits.

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?

The description is front-loaded with the use case and is organized logically from purpose to fields, pinType behavior, pagination, and account selection. It is somewhat long for a list tool and repeats the link/title lookup guidance, but nearly every sentence carries operational value.

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?

Given an output schema and annotations that already cover safety, the description supplies everything else an agent needs: scope, sibling distinctions, field meanings, pinType edge cases, date filtering, pagination completion rules, ID semantics, credit cost, and account-selection ambiguity. Nothing material for correct invocation appears missing.

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 real meaning beyond the schema: it explains that ORIGINAL and SAVED can both miss an account's own Pin saved to another board, that ALL plus isRepin is needed to count every save, that startDate and endDate may be supplied alone, and that pinId is a Pinterest ID rather than a Tailwind postId. It leaves limit and accountId mostly to the schema, so it is strong but not exhaustive.

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: every Pin on the Pinterest account, optionally within a date range, for inventory, export, weekly counts, or lookup by link/title. It explicitly distinguishes this from list_posts and list_top_pins, so an agent can select it confidently without opening sibling 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?

It names the alternatives and the conditions that select them: list_posts covers only Tailwind-scheduled Pins and list_top_pins returns ranked winners, neither being a complete inventory. It also states there is no search filter, explains the pagination loop, and instructs the agent to ask the user which account to use when multiple accounts exist.

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