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

Annotations already declare destructive, idempotent and open-world traits, so the bar is lower. The description adds real value beyond them: the optimistic-concurrency protocol, the current_version field on conflict, release semantics on done/open, and the lease_token precondition. It does not state auth requirements or whether a replaced summary is recoverable.

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 short imperative sentences, front-loaded with the operation and concurrency model, and every sentence adds an actionable fact. No filler or restatement of the tool name.

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 destructive, idempotent mutation with no output schema, the description covers the concurrency contract, conflict handling, claim/lease preconditions, and retry guidance. What remains thin is the interaction with siblings (post vs reply vs update) and any permission requirements.

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 75%, so most parameters are self-documented, and the baseline would be 3. The description adds context the schema doesn't: lease_token is required only while a claim is active, expected_version is used for optimistic concurrency, and a conflict surfaces current_version for rereading.

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 set (change status, replace summary) on a specific resource (thread) and names the concurrency mechanism. An agent can identify the operation clearly, though it never explicitly distinguishes this from relay_post/relay_reply for the 'change status' aspect.

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?

Gives concrete operating conditions: read latest version first, lease_token required under an active claim, done/open releases the claim, and how to react to a version conflict. It stops short of naming which sibling to use for posting replies or claiming, so routing is inferred rather than explicit.

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