pin_message

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

Annotations already indicate a mutating but non-destructive action (readOnlyHint=false, destructiveHint=false), and the description adds little beyond 'its channel'. It does not disclose permissions, whether pinning is idempotent, failure scenarios, or side effects. Thus it provides no behavioral context beyond the annotations.

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?

The entire description is one concise sentence with the verb front-loaded and no filler words. It is appropriately minimal for a straightforward action, earning maximum conciseness.

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 tool with two required parameters and no output schema, the description omits how to obtain the IDs, what success looks like, and references to related tools like list_pins or unpin_message. It does not provide enough surrounding context to guarantee correct invocation in varied workflows. Thus the definition is incomplete despite its clarity.

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 has 0% description coverage, so the description must carry parameter meaning, but it only refers to 'a message' and 'its channel' without mapping to channel_id and message_id or explaining their relationship. 'Its channel' weakly implies the message's home channel, but does not clarify ID formats or constraints. This is insufficient compensation for the schema gap.

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?

Description uses a specific verb 'Pin' with resource 'a message' and location 'in its channel', making the operation unambiguous. It is distinguishable from siblings like unpin_message and list_pins by the action word. Even with a null title, an agent can infer exactly what the tool does.

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 offers no explicit when-to-use guidance or alternatives. It does not mention unpin_message or list_pins for related workflows, nor preconditions such as message existence or permissions. The only usage implication is the imperative phrasing itself.

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