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

Goes well beyond the annotations: it discloses the attribution precondition (active lease, or an owned acting_worker_id, or a human assignee/org owner), the exact failure mode (422 with nothing written), and the non-obvious rule that the actor is never inferred from the assignee. For a mutation tool whose annotations only say readOnly=false/destructive=false, this is rich, decision-relevant 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?

Front-loaded with purpose, then constraints, then error behavior, ending with the API reference. It is a dense paragraph rather than discrete sentences, but nearly every clause carries operational information; the reference link is the only arguably optional element.

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?

Covers purpose, preconditions, and failure behavior for a 3-parameter tool with no output schema. The one omission is what a successful call returns/adds to the event log, though the append-to-log framing makes that largely self-evident.

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 already 100%, so the baseline is 3, but the description adds real meaning on acting_worker_id: that lease precedence overrides it and that ownership is verified. That is semantics the schema does not fully convey, lifting it above baseline.

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: 'Append a progress note to a task's event log', with the intent (teammates following work without asking) made explicit. It is clearly distinguishable from add_artifact or task-mutating siblings, though it never names add_comment or log_project_event as the closest alternatives, so the boundary against those is left to inference.

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?

Gives concrete when-to-use guidance ('at each meaningful step — decisions, blockers, findings'), which tells the agent the cadence and content type expected. It does not, however, state when NOT to use it or explicitly route to a sibling such as add_comment for discussion-style messages.

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