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

With readOnlyHint=false already covering the write nature, the description adds the crucial consequence that the existing capability DAG is overwritten and replaced with a fresh one — an effect the agent could not infer from annotations. There is mild tension with destructiveHint=false since prior decomposition output is discarded, but the operation is a regenerable recompute rather than an irreversible deletion, so this is not a true contradiction.

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?

Three short sentences, front-loaded with the action, then the effect, then the motivating scenario. No redundancy and nothing that fails to earn its place.

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 single-parameter, no-output-schema mutation, the definition covers action, side effect, and motivation, which is enough to invoke it correctly. It could say slightly more about what the fresh decomposition replaces or whether it is asynchronous, but 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?

Only one parameter and schema description coverage is 100% ('Request ID to decompose'), so the schema already carries the semantics. The description never mentions requestId or what constitutes a valid/re-decomposable request, adding nothing beyond the schema — baseline 3 applies.

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?

States a specific verb+resource ('Re-trigger decomposition of an existing capability request') and the qualifier 'existing' plus 'Re-trigger' cleanly separates it from creation siblings like pcc_submit_request and read siblings like pcc_get_request_dag. An agent can pick this tool without opening any schema.

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 a concrete trigger condition ('Useful after updating the description or budget'), which is real when-to-use guidance rather than generic filler. It stops short of naming alternatives or stating when NOT to re-decompose (e.g. while a decomposition is already running).

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