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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=true and openWorldHint=true, but the description goes beyond them by specifying WHAT makes the call idempotent: the combination of eventId and exact bytes. That is non-trivial retry guidance a caller needs. It still omits what happens on success (queued vs delivered) and any auth/error behavior, so it is not 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?

A single well-formed sentence with the operation front-loaded and zero filler; nothing is redundant. It is arguably too terse for a five-required-parameter write tool, which keeps it from a 5.

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 write tool with five required parameters, 0% schema coverage and no output schema, the description supplies only the idempotency rule. It never explains the auth token, the hookId format, the accepted content types or the body encoding/size limit, so an agent must reverse-engineer most of the contract from the raw schema.

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 description coverage is 0% across five required parameters, so the description must carry the explanatory load. It names only eventId (and only in the context of idempotency); token, hookId, contentType and bodyBase64 receive no semantic explanation, leaving the discriminating token pattern and the base64 size cap undocumented in prose.

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 (enqueue) and resource (an event), plus the target scope ('your verified receiver'), which cleanly separates it from sibling reads like get_hook_delivery and lifecycle tools like register/verify/revoke_destination. It does not explicitly name a sibling alternative, so it stays 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?

The phrase 'for your verified receiver' implicitly encodes a prerequisite (the destination must already be verified via verify_destination/register_destination), which is useful context an agent can act on. However, there is no explicit when-to-use statement, no exclusion, and no named alternative among the six siblings.

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