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

Annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the bar is lower, and the description adds real context beyond them: the lease is exclusive and expiring, a concurrent holder produces a conflict, and the returned lease_version must be preserved for subsequent mutations. It still omits what happens on expiry or what the response contains.

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 tight sentences, front-loaded with the action, then the durability rule, then the conflict condition. No filler and every sentence carries information.

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 mutation tool with no output schema, the description covers the conflict semantics and the lease_version preservation rule, but leaves duration_seconds semantics (default 900, min 60, max 3600) and the shape of a successful acquisition unaddressed. Adequate but with clear 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 only 33% -- only idempotency_key is documented in the schema. The description mentions lease_version (not a parameter at all) while saying nothing about task_id or duration_seconds, so it does not compensate for the undocumented 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+resource ('Acquire ... task lease') and adds scope qualifiers ('exclusive expiring') that an agent can act on. It does not explicitly distinguish itself from the sibling renew_task_lease, but the acquire/renew distinction is inferable.

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 description notes that 'another active holder causes a conflict,' which hints at a failure mode, but it gives no when-to-use guidance and never names the obvious alternative sibling (renew_task_lease) or when acquiring versus renewing is appropriate.

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