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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description adds the blast radius that matters for a mutation: posts with their own boardId and already-scheduled/published pins keep their board. What is missing is any mention of permission/auth requirements or what happens on an invalid boardId.

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?

Three short, front-loaded sentences: effect, constraint, then usage rule and alternatives. Nothing is padding, and the routing guidance comes early enough to prevent a wrong call.

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 values need not be described; for a single-parameter mutation the description covers effect scope, prerequisite, exclusions, and sibling routing. Nothing an agent needs in order to call it correctly is absent.

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 baseline is 3. The description adds real meaning beyond the schema: boardId must exist on the connected account's board list obtained via list_pinterest_boards, and it defines what the value means semantically (the target of an implicit default).

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 first sentence states a specific verb (set) plus resource (default Pinterest board) and, crucially, the trigger scope: new pins with no boardId. It also distinguishes itself from sibling list_pinterest_boards and from the per-post boardId mechanism, so an agent can tell it apart without opening a 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?

Explicit when-to-use ('only when the requester asks to change the default board') and explicit when-not ('not to place one pin'), with the correct alternative named for the excluded case ('set boardId on the post'). Prerequisite is also stated: boardId must come from list_pinterest_boards.

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