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

Annotations only cover the safety profile (not read-only, idempotent, non-destructive); the description adds the lease mechanism, the requirement to keep runId and leaseToken, the renewEverySeconds heartbeat obligation, the consequence of lease expiry (task offered to someone else), and the semantics of the already_claimed and attention_queue_full refusals. No contradiction with idempotentHint=true or destructiveHint=false.

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-loads the critical timing instruction, then explains lease mechanics, then the two refusals, then the next step. Every sentence carries operational weight, with no filler or repetition.

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?

There is no output schema, so the description correctly compensates by naming the return values (runId, leaseToken) and explaining what to do with them. For a single-parameter state-mutating tool, 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 coverage is 100% and there is only one parameter (id, documented as 'Task ID'). The description adds no syntax or format detail for id beyond what the schema provides, so the baseline 3 applies; it does usefully name the returned runId and leaseToken, but those are outputs, not 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: it claims the task with a lease, moves it to Doing, and starts cycle-time tracking. This clearly distinguishes it from siblings like complete_task, report_progress, and move_task, which an agent can route between 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 says when to call it ('the moment you begin executing a task — BEFORE doing the actual work') and names the follow-up alternatives (report_progress while working, complete_task when done). It also pre-declares the two normal refusals so the agent does not misinterpret them as errors.

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