Signal agent is working

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

Annotations only declare readOnly=false, destructive=false, openWorld=false; the description adds lease ownership semantics, the 409 conflict condition and correct response, the non-effect on turn state, and the UI consequence ('Agent is working…' vs stale stopped hint). That is substantive behavior an agent cannot infer from the structured fields.

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 action, then discovery, cadence, failure handling, and the latex exclusion in descending order of importance. Every clause carries operational information; nothing restates the title or schema verbatim.

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 lease/heartbeat tool with no output schema and only generic annotations, the description covers acquisition, renewal cadence, conflict handling, failure mode, side effects, and one platform exclusion. An agent has everything needed to call it correctly and to recover from the 409 case.

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; the description earns above that by clarifying that `owner` must be YOUR session id and by explaining the cross-owner conflict outcome that makes the parameter's value matter. `message` is only implied ('status shown in the banner'), so it stops short of 5.

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 ('Claim or renew your lease on a review') plus what it is not ('Does NOT change whose turn it is'), which distinguishes it from siblings like hand_back and get_status. It also names the sibling tools used for discovery, so the agent can place it in the workflow without opening schemas.

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?

Explicit lifecycle guidance: poll list_reviews / get_status for reviews with turn=='agent', call this immediately, then periodically while working. It also gives a when-not ('Not available on a kind=latex review') and prescribes the recovery action on 409 (back off and skip).

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