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

Goes well beyond the annotations (which only cover idempotent, non-destructive, non-read-only). It discloses the status-history side effect at 100, the no-op on status below 100, the milestone snapping rule, and the permission model (any team role, Guest excluded) — exactly the behavioral context an agent needs before a mutation.

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 the core action, then side-effect rules in a logical order, and every sentence carries information. The parenthetical asides ('any team role — a Guest can change nothing') are slightly compressed to the point of ambiguity but not wasteful.

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?

With no output schema, the description closes the loop by stating it returns the task after reconciliation. Combined with permission requirements, side-effect disclosure, and parameter edge cases, nothing material is missing for a 2-param mutation.

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, but the description adds real meaning: the 0-100 bounds are restated and the milestone snap-to-0 behavior changes how an agent should choose the value. The 'id' parameter is left entirely to the schema.

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 ('Set a task's percentComplete') plus the accepted range, which cleanly separates it from set_task_status and update_task among the siblings. An agent knows exactly what this mutates without opening the 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?

The reconciliation paragraph effectively tells the agent when to reach for this versus set_task_status: progress only touches status at 100, otherwise status is untouched. It stops short of naming set_task_status or update_task explicitly as alternatives, so the routing is inferential rather than stated.

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