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

Annotations already declare destructive/idempotent/non-readonly, and the description layers on genuinely new behavior: the return shape { updated, skipped, errors } for partial-success observability, skip-vs-error semantics for unauthorized tasks, and a single parent-auto-close rollup per batch rather than per task. These are consequential side-effect details the annotations do not carry.

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?

Five tight sentences, each earning its place, with the core purpose and the update_task alternative front-loaded. No filler or redundancy.

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?

No output schema exists, but the description supplies the return shape and partial-success semantics, plus batch limits and side-effect behavior. Nothing an agent needs to invoke it correctly 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?

Schema description coverage is 100%, so dryRun, status, and taskIds are already fully documented, and the description's 'Up to 50 task ids per call' merely restates maxItems: 50. It adds no syntax or format meaning beyond the schema, so the 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 and resource ('Flip status on multiple tasks in one call') and immediately distinguishes itself from the single-task sibling update_task. An agent can tell exactly what this does and how it differs from update_task and bulk_update_tasks 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?

Explicitly routes the agent: 'Use this instead of N update_task calls when marking siblings DONE / blocking a batch / reopening a set.' It names the alternative and the conditions that select this tool, covering when-to-use and when-to-use-something-else.

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