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

Annotations already declare destructiveness and idempotency, and the description adds operational context: changes are effective immediately, activation is provider-limited, and lost-response handling should use channel_read. It does not fully spell out the consequences of disabling a channel, but it adds substantial behavioral guidance beyond the annotations.

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 core action and timestamp dependency are front-loaded, and the remaining sentences cover relevant edge cases without excessive length. Some phrasing is unusually terse, such as 'failure is not implied,' which makes the structure slightly harder to parse.

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?

Given the nested schema, full parameter descriptions, annotations, and output schema, the description covers the important operational edge cases: provider-specific activation, immediate effect, lost responses, and stale timestamps. The main omission is a clear statement of what disabling or changing status means for the channel, though destructiveHint already signals risk.

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 schema already documents data, agent_id, channel_id, and expected_updated_at thoroughly. The description reinforces that status/reply mode are supplied and expected_updated_at comes from channel_read, but adds little beyond the schema's own parameter descriptions.

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?

The description states a specific action and resource: changing supplied status/reply mode, with an immediate effect. It also distinguishes activation paths from LINE, Widgets, and other providers, though the phrasing is dense rather than plainly front-loaded.

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?

It gives concrete usage context: use channel_read's timestamp, only Widgets activation belongs here, LINE activation goes to line_connection_verify, and other providers use existing connection settings. It also advises reading state after a lost response and avoiding blind replay with a stale timestamp.

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