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

Beyond the annotations, the description discloses important behavioral traits: required webhook.manage permission, bounded authorization scope, no real-world side effects, the test's free/fictional nature, and the precise meaning of success. It also advises reusing the exact idempotency_key after an uncertain mutation, which aligns with the idempotentHint annotation and adds practical operational context.

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 description is compact yet information-dense, front-loading the core operation in the first sentence and then layering constraints, permissions, limitations, and a documentation link without redundancy. Every sentence adds operational value.

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 test tool with an output schema and annotations, the description covers the key contextual aspects: what the sample test does, side effects it avoids, required permissions, authorization scope, idempotency behavior, and proof semantics. It is slightly incomplete only because expected_revision is not given any meaning, and the exact conditions for 'if needed' are left vague.

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%, so the description carries the full burden for explaining the three parameters. It gives some guidance for idempotency_key ('reuse the exact idempotency_key and input after an uncertain mutation') and implicitly associates endpoint_id with 'this webhook', but expected_revision is never explained at all. This is a meaningful 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?

The description clearly identifies the action ('Run the Sample test'), the resource (a webhook endpoint), and the specific behaviors that distinguish this tool from siblings: it opens/scans a fictional Mojave sample letter, delivers real inbound.pages_ready / inbound.keywords_matched events, and computes a verdict from the receiver's HTTP result. It also explicitly states what success does and does not prove, making the tool's role unambiguous even next to test_webhook_endpoint.

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 description gives clear usage context: it is for verifying transport receipt and optional keyword matching, not agent processing, and it emphasizes there is no mail/charge/email/facility side effect. It does not explicitly name sibling alternatives or give a direct 'use this instead of X' rule, but the behavioral boundary is clear enough for an agent to choose correctly.

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