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

Annotations already cover read-only and open-world behavior, and the description adds genuinely new context: the operation costs 1 credit, only public pin data is returned, and two specific values (destination link, save count) live under `raw` rather than at top level. That last point is real return-shape guidance absent from any structured field.

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 sentences, front-loaded with the resource and its payload, then the `raw` caveat, then cost. Nothing is redundant and every clause carries information.

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 return-value burden and does so by listing the fields plus the `raw` container, and it discloses the credit cost. The one real gap is `cache_max_age`, which is left entirely unexplained for a simple two-parameter read tool.

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 only 50%. The `url` parameter is well documented in the schema with a concrete example, but `cache_max_age` is undocumented in both schema and description, and the description adds no parameter-level meaning at all — it never mentions either input.

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 names a specific resource ('Pin details') and enumerates exactly what is returned: title, description, reactions, comments, shares, and full-resolution media. That is enough to separate it from pinterest_search and pinterest_board by resource, though it never names those siblings explicitly.

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?

Usage is only implied: you supply a pin URL and get that pin's details. There is no statement of when to prefer this over pinterest_search (to find a pin) or pinterest_board (for board contents), and no preconditions or exclusions are given.

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