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

Annotations already declare readOnlyHint=false and openWorldHint=true, and the description meaningfully reinforces this by warning that a real HTTP request is made to the customer's URL and by offering dry_run as the safe mode. Beyond that it discloses nothing about failure behavior, response shape, or whether the test event counts toward webhook stats or rate limits.

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?

Three short sentences, front-loaded with what it does and immediately followed by the side-effect warning and the escape hatch. Nothing is wasted and the most decision-relevant fact (real HTTP request) appears early.

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 tool with no output schema, the core risk (an outbound request to a customer URL) and its mitigation (dry_run) are covered. However, the description never indicates what the call returns on success or failure, which is the main thing an agent would need to interpret the result of a test.

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 in structured fields. The description adds only modest meaning: the payload is a fixed sample rather than caller-supplied, and dry_run suppresses the actual send. Baseline 3 is appropriate when 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?

The description gives a specific verb and resource ("Send a sample event payload to a webhook's URL") plus the intent ("check that the endpoint receives it"), so an agent can distinguish it from get_webhook or toggle_webhook. It does not differentiate from the near-identical sibling test_transactional_webhook, which is the one sibling it most needs to be separated from.

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 context is clear: use it to verify an endpoint receives events, and use dry_run when you only want to inspect the target URL. There are no explicit exclusions and no routing to test_transactional_webhook as the alternative for transactional hooks, which keeps it below a 5.

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