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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered structurally. The description adds genuinely new behavioral context: signing-in tests using this account will stop running until the credential is re-added or the tests are edited. It does not state whether the deleted account can be recovered or whether other resources reference it.

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 short sentences, front-loaded with the action and immediately followed by the consequence. Nothing is redundant or padded.

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 single-parameter destructive delete with full annotation coverage and no output schema, the description supplies the key operational consequence an agent needs. It could add whether the deletion is reversible or what happens to the credential's other associations, but the essential picture is complete.

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?

There is a single parameter with 100% schema description coverage, documenting it as an account id in the cr_… format. The description adds no further meaning beyond the schema, so the baseline of 3 applies.

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 and resource, 'Delete a sign-in account', which is unambiguous and matches the tool name. It does not explicitly distinguish itself from siblings like add_credential or list_credentials, but the action and target are clear enough that no schema lookup is needed.

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: by explaining that dependent tests will stop running, it signals this is a consequential operation to use deliberately. It offers no explicit when-to-use versus alternatives (e.g., list_credentials to verify the id, or re-adding via add_credential), so guidance is contextual rather than stated.

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