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

With annotations already declaring destructiveHint=true and readOnlyHint=false, the description adds substantial context: replays sit outside the monthly event quota but inside a daily replay limit and the compute allowance, held-for-quota events bill as new events, and non-idempotent receivers will process the event twice. That is exactly the kind of downstream consequence an agent cannot get from annotations alone.

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-loads the action, then layers billing and idempotency caveats in three dense sentences with little waste. Slightly long on parenthetical tool references, but every clause carries information.

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 two-parameter mutating tool with no output schema, it covers the important behavior: quota treatment, billing consequences, and duplicate-processing risk. It stops short of error/failure conditions or what a replay returns, but the essentials are present.

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 both parameters are already documented; the billing note in the description largely restates the schema's own wording on 'id'. Baseline 3 applies since the schema does the heavy lifting.

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+resource: re-send a stored event to its destinations. Clear and concrete. It does not explicitly differentiate from the close sibling anyhook_replay_failed, which also replays, so it falls short of a 5.

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?

Usage is only implied ("while debugging"), and no alternative is named. It never says when to pick this over anyhook_replay_failed or anyhook_undelivered, which given that sibling set is a real gap.

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