pinned

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

No annotations are provided, so the description carries the full burden. 'List' implies a read operation, but nothing is said about how the chat is resolved (there are zero parameters), whether authentication is required, ordering, or pagination behavior.

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 short sentence, front-loaded with verb and resource, with no filler. It is arguably too terse for the surrounding gaps, but it wastes nothing.

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 annotations, no output schema, and no parameters, the description is the only source of context and it supplies just one line. It omits how the target chat is determined, the return shape, and ordering/limits, leaving an agent guessing about the most important scoping question.

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?

The schema has zero parameters, so the baseline is 4 and there is no parameter syntax for the description to add meaning to. The one semantic gap is that the chat context is implicit and unexplained, but that is not a schema-documented parameter.

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 states a specific verb and resource ('List pinned messages') and the scope ('of a chat'), which distinguishes it from the sibling 'pin' (which pins) and 'messages' (which lists all messages). It is clear on its own, though it never explicitly names or contrasts with those siblings.

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?

There is no statement of when to use this tool versus 'messages' or 'pin', no preconditions, and no note about which chat is targeted. The usage is only inferable from the name and verb.

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