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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description goes further by specifying what is destroyed ("The previous values are overwritten") and adding a side effect the annotations cannot express: dependent dates are recalculated. It also discloses the write-permission requirement.

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 dense sentences with the highest-value facts front-loaded (what changes, what is overwritten, recalc side effect). The field enumeration partly restates schema property names, but it functions as a fast scannable summary rather than filler.

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 15-parameter mutation with no output schema, the description covers overwrite semantics, downstream recalculation, permissions, and constraint rules well. It never states whether omitted fields are left untouched or that the response returns the updated task, which are the remaining gaps.

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 baseline is 3, but the description adds meaning on top: three-point estimates are tied to the Monte Carlo simulation, and the constraint enum is annotated with the rule that all kinds except asap/alap require constraintDate. The reference to a generic "position" is slightly looser than the actual parentTask/afterTask parameters.

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 and resource ("Changes an existing task") and enumerates exactly which attributes are mutable, so the agent can distinguish it from planitude_add_task and planitude_set_progress without opening the schema. The scope statement is concrete and unambiguous.

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?

Explicitly routes progress updates away ("For progress use planitude_set_progress") and defines when a constraintDate is required, which is real when-to-use guidance. It does not address alternatives for rescheduling or structural moves, but the highest-risk confusion is resolved.

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