Create pin

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

Annotations already convey that this is a non-read-only, non-idempotent, non-destructive, open-world write. The description adds genuinely new behavioral context: the exact scopes needed (pins:write, and pins:write_secret on secret boards) and the required inputs. It does not discuss failure modes or rate limits, so it stops short of a 5.

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 with no filler; the core action comes first and the constraints follow. The middle sentence is mildly redundant with the schema's required list, which is the only thing keeping it off 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?

For a 10-parameter create tool, the description correctly delegates the complex media_source variants to the schema and covers the points the schema cannot express (scope requirements). With no output schema, it could have hinted at what is returned (e.g. a pin id), which is the one remaining gap.

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%, and the media_source union already documents all four variants and their required fields in detail, so the schema carries the parameter burden. The description's mention of board_id and media_source only restates what the schema already marks as required, adding no new semantics.

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 (create a pin) and scopes it to "one of the authenticated user's boards." It does not, however, distinguish itself from the very similar sibling pinterest_save_pin, which an agent must choose between.

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 gives the prerequisites for calling (a board_id and a media_source must be supplied) and the OAuth scopes required, which is useful context. But it never says when to prefer this over pinterest_save_pin or pinterest_update_pin, so tool selection between near-identical siblings is left to inference.

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