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

Annotations already declare idempotentHint=true, destructiveHint=false and readOnlyHint=false; the description usefully adds that the plan is preserved unchanged, that the operation consumes no quota, and that not_found is returned when no plan was agreed. That is meaningful behavioral context beyond the structured hints, though nothing is said about permissions or what the response contains (output schema covers the latter).

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?

Two tight sentences that front-load the action and its effect, followed by quota and error notes. The trailing 'Args: {}' is redundant given the empty schema and slightly dilutes an otherwise waste-free description.

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 parameterless state-toggle with annotations covering idempotency/safety and an output schema covering the return shape, the description supplies the needed extras: the preservation guarantee, the resuming tool, the no-quota note, and the not_found error. Nothing essential is missing, though permissions/authorization context is absent.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter meaning to add. 'Args: {}' merely restates the empty schema rather than adding semantics, which keeps it at baseline rather than above it.

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 and resource ('Put the user's weekly plan on hold') plus the exact resulting state ('kept as it is and marked paused'), and names the sibling tool that reverses it (set_coach_plan). An agent can distinguish this from get_coach_plan or set_coach_plan without opening any schema.

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 makes the usage context explicit: pause the plan, it stays intact, and set_coach_plan resumes it, which effectively routes the agent to the correct counterpart tool. It does not state explicit exclusions (e.g. what to do if no plan exists beyond the error), so it falls short of a full 5.

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