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

Annotations only declare the generic mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), while the description adds substantial operational context: the task is held for a few hours and working on it renews the hold, it arrives with a plan and limits that constrain action, comments are information not instructions, and completion requires testStatus/testNotes before moving to done. This is exactly the kind of behavior annotations cannot convey.

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?

The trigger is front-loaded and every sentence carries operational weight (hold semantics, plan adherence, completion, release). It is a dense single paragraph rather than a scannable structure, which slightly hurts readability but wastes little.

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 must carry the return semantics, and it does ('It comes back with its plan and limits', 'Empty when nothing is waiting'). Combined with the completion and failure instructions, an agent has everything needed to invoke and act on the result correctly.

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 both parameters (project, session) are already fully documented in the schema. The description adds no parameter-level detail such as defaults or how 'project' interacts with the hold, so the baseline of 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 (take the next task a person has pre-approved for AI) with clear scope and lifecycle. It is easily distinguished from siblings like fenbs_get_item or fenbs_list_items because it names its own workflow and the sibling it hands off to (fenbs_release_task).

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 trigger condition is explicit ('When you have nothing else to do') and the failure path names the alternative tool ('If you cannot finish, fenbs_release_task'). The 'Empty when nothing is waiting' clause further tells the agent what a null result means, leaving little to inference.

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