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

The description extensively discloses behavioral requirements beyond annotations: attribution rules, lease or acting_worker_id requirements, the 422 rejection outcome, the guarantee that nothing is written on failure, and that the actor is never guessed. This is exactly the kind of behavioral context that annotations alone do not provide.

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 dense but every sentence earns its place: purpose, timing, attribution, failure mode, and explicit non-guessing guarantee. It is front-loaded with the core action and use context, and the length is justified by the authentication complexity.

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?

The description covers what the tool does, when to use it, authentication prerequisites, and failure behavior. No output schema exists, so a mention of the return value or confirmation payload would be nice, but it is a minor omission given the side-effect-focused nature of the tool.

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 100%, so the baseline is 3. The description goes beyond the schema by explaining who may act without a worker identity (human assignee or org owner) and what happens when no valid actor is supplied. This enriches the acting_worker_id semantics meaningfully.

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 names a specific action and resource: 'Append a progress note to a task's event log.' It also clarifies the purpose ('so teammates can follow the work without asking'), which helps distinguish it from generic add_comment. It could more explicitly contrast with add_comment or other similar tools, but the action is clear.

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 gives clear usage timing: at each meaningful step — decisions, blockers, findings — as part of the Tango working agreement. It also states the condition under which the tool should NOT be used implicitly by requiring valid attribution. It does not explicitly name alternatives, but the context is strong enough for an agent to route correctly.

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