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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so safety and repeatability are covered structurally. The description adds a concrete failure mode not present in the annotations: referential-integrity blocking until dependent API tests are reassigned or removed. Auth requirements and confirmation needs are still unstated.

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?

Two tight sentences: the action first, then the blocking condition. No filler, and the constraint is front-loaded rather than buried.

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?

A destructive one-param tool with no output schema and full annotation coverage needs little more; the failure precondition is the essential missing piece and it is supplied. Only the origin of a valid credentialId is left implicit.

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?

Only one parameter with 100% schema description coverage, so the schema already documents credentialId fully. The description's 'by id' adds no format, sourcing, or validation detail beyond that, which is the expected baseline when the schema does the work.

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 (delete) and resource (stored API test credential) with the keying field (id). Combined with the name, an agent can distinguish this from create_api_test_credential and list_api_test_credentials without opening any schema.

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?

Gives an explicit precondition: it fails while any API test still references the credential, and instructs the caller to reassign or delete those tests first. It does not, however, point at the sibling that surfaces deletable credentials (list_api_test_credentials) or state when deletion is unnecessary.

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