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

Annotations already declare idempotentHint=true and destructiveHint=false, but the description adds useful behavioral detail: it is reversible, sends no message, deletes nothing, returns already_in_state when no change occurs, and requires write scope. Some of this overlaps with annotations, but the already_in_state response and write-scope requirement add real context.

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 description is short, front-loaded with the action, and every sentence adds value: scope, reversibility, no-send/no-delete behavior, idempotent response, and permission requirement. There is no padding.

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 simple one-parameter mutation with no output schema, the description covers the critical behavioral details an agent needs: effect, non-effects, reversibility, idempotency, response behavior, and required write scope. Nothing essential is missing.

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?

There is one parameter and schema description coverage is 100%, so the schema already documents conversation_id clearly. The description does not add syntax or semantic detail beyond the schema, making the baseline 3 appropriate.

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: pinning a conversation to the top of the inbox, and clarifies it applies to one-to-one or group conversations. It does not explicitly name the sibling unpin tool or otherwise differentiate among alternatives, so it is clear but short of the full 5 criteria.

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 clear usage context: pinning a conversation, applicable to both two-person and group conversations. It does not state when not to use the tool or explicitly route the agent to ficiel_unpin_conversation for reversal, leaving that to inference from “Réversible”.

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