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

Annotations already cover safety (destructiveHint=false, idempotentHint=true, readOnlyHint=false), so the description's contribution is the state semantics: timers stop and stay stopped until resumption. That is real behavioral context an agent could not get from the annotations. It stops short of saying what happens to an in-flight step or whether paused state persists indefinitely.

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?

One sentence, front-loaded with the action, and every clause carries information (scope of the pause plus the timer consequence). No padding or restatement of the title.

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 one-parameter control operation with full schema coverage and annotations, the description covers the essential effect and its reversibility. The remaining gap is minor: it does not say what the caller gets back or whether a currently executing step completes before the pause takes effect.

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% with a single required UUID parameter fully documented in the schema, so the baseline of 3 applies. The description adds no extra meaning about the run identifier or how to obtain one (e.g. via list_runs or get_run).

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 ('Pauses a run') and adds a scope qualifier ('where it stands'). The reference to 'until it is resumed' implicitly signals the counterpart operation, but it never names resume_run or any other sibling, so differentiation is left to the agent.

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 phrase 'until it is resumed' implies this is a temporary suspension rather than a termination, which implicitly contrasts with stop_run, but no explicit when-to-use or when-not-to-use guidance is given. The agent must infer the choice between pause_run, stop_run, and resume_run from names alone.

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