Get pinned messages

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

No annotations are provided, so the description bears full responsibility. It adds behavioral context beyond the schema by stating the ordering ('newest first') and that it returns all pinned messages. However, it omits details like required permissions (e.g., 'Read Message History') or whether the response includes full message objects. Still, the added ordering information is valuable.

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?

A single sentence front-loads the core action and ordering. Every word earns its place; no redundant or filler content. Ideal length for conveying essential 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?

Given the simplicity of the tool (fetching pinned messages) and no output schema, the description covers the key points: what it does and ordering. It does not specify the output format (e.g., array of message objects) but this is common for fetch tools. Slightly more detail on output could improve completeness, but it is mostly adequate.

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%, so the schema already documents both parameters. The description does not add additional semantics or formats beyond the schema (e.g., no explanation of how to specify channel by name vs ID). Baseline score of 3 is appropriate since the schema is self-sufficient.

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 'Fetch all pinned messages in a channel, newest first.' clearly states the verb ('Fetch'), resource ('pinned messages'), and scope ('in a channel'). It distinguishes from sibling tools like 'pin_message' and 'unpin_message', which manage pins rather than retrieve them, and 'read_messages', which fetches general messages.

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 implies use when retrieving pinned messages but provides no explicit guidance on when to avoid it or alternatives. For example, it does not mention that 'read_messages' might be used for non-pinned messages or that permissions are required. The context is clear but lacks comparative direction.

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