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

Adds real behavior beyond the annotations: the lease_token re-issuance semantics and the null-empty state are not captured by readOnlyHint=false/idempotentHint=true. It stops short of stating auth expectations or what happens to an abandoned task/lease expiration, so not a full 5.

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 result, then gives the workflow in imperative order in a few tight sentences. Nothing redundant and no wasted clauses.

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?

Covers the return shape, the null case, and the submit loop, which is what an agent needs to drive the task cycle. Lacks details on lease expiration or authorization, minor given the focus, but keeps it from a 5.

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 agent_key is already documented (pba_ key, optional when carried by URL/Bearer). The description does not add parameter-level detail, 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 action (retrieve your next already-claimed task) plus the payload shape (what to do, answer shape, reward, run_id). Clearly distinguished from siblings like claim_run, get_run, and submit_result by the 'already claimed for you' framing.

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 an explicit workflow: call next_task, then submit_result with the run_id, then call next_task again. Also states the edge case (null = nothing waiting) and the re-invocation rule (calling again before submitting returns the same task with a new lease_token).

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