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

Beyond the annotations (destructiveHint=true, idempotentHint=false), the description discloses that the original is archived and recoverable, that other plan entries are untouched, that a reason lands on the archive + audit log, and that first use may require manager approval. These are meaningful behavioral details the 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 purpose is front-loaded and each paragraph earns its place (purpose, routing, approval flow). However, the write-tier paragraph is dense and somewhat cryptic ('the card is the yes'), and the routing section partially repeats the first sentence's scoping, so it is slightly longer than strictly necessary.

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 destructive, approval-gated mutation with no output schema, the description covers the key operational facts: when to use it, what is and isn't affected, recoverability, and the approval/re-ask behavior. It omits only minor details like expected confirmation output, but the annotations plus full schema coverage make the tool safely callable.

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 schema already documents all six parameters. The description adds only marginal parameter context — e.g., implying the typical split shape via '(intake + finish)' and that pieces are usually supplied by exhaustion-recovery stamps — but does not materially extend what the schema says. Baseline 3 is 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 first sentence states a specific verb and resource ('Split ONE oversized activity into smaller activities') with a clear scope qualifier ('without regenerating the rest of the plan'). It also names the sibling it is not (recalibrate_agent_jd), so an agent can reliably distinguish it from nearby plan-mutation tools.

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?

Provides an explicit trigger condition ('when a run hit the continuation safety backstop while still progressing') and an explicit exclusion ('never recalibrate_agent_jd for this class'). The write-tier approval note adds operational when-to-call guidance ('Call it on the first clear ask'), leaving little to inference.

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