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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds value beyond them by disclosing that error state and last-checked timestamps are returned, that account-level limits come along, and that the call is free. It does not cover result volume or pagination behavior for accounts with many monitors, which keeps it below a 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-loaded with the verb and scope, and every clause maps to a returned field or a chaining rule, so little is wasted. It is dense to the point of being run-on, packing limits, the event-id handoff, and cost into one long span, but that density is informative rather than padding.

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 single-optional-parameter read tool with full annotation coverage and an output schema that already defines return shape, this is sufficient: scope, contents, the hasNew side effect, account limits, the get_new_videos handoff, and cost are all stated. Nothing an agent needs in order to call it correctly is missing.

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 would be 3, and the description earns the extra point by naming the field as last_event_id and explaining the round-trip: feed it into get_new_videos as since, and it drives each monitor's hasNew flag. It does not say what happens with a stale or invalid event id, which is the only real gap.

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 (list the monitors on this account) and then enumerates exactly what each entry discloses: watched resource, check frequency, transcript delivery, last check time, last error, webhook presence. That inventory distinguishes it cleanly from create_monitor, delete_monitor, and check_monitor_now, so an agent can identify it without opening the 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?

Gives clear context for use (see all monitors plus account limits) and a concrete next-step rule: take last_event_id and pass it to get_new_videos as since. It also flags that the call is free, which supports a polling strategy. It stops short of explicit exclusions, e.g. when to prefer check_monitor_now, but the surrounding siblings make the boundary reasonably obvious.

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