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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description goes well beyond them: the code is single-use with a 15-minute expiry, a second use is refused without mutating credentials or settings, retries are keyed by op_key, and revoke_others' blast radius is itemized (other credentials, capabilities, codes, webhook, pending email changes) with the verified email explicitly preserved.

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 sentences, all front-loaded with the constraint (single-use, 15 minutes) before the retry contract and the destructive branch. Dense but every clause carries behavior; only the slight overlap between the revoke_others sentence and the schema's identical description 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 destructive, non-read-only mutation with no output schema, the description covers the failure mode, the idempotent retry path, and the full destruction set, which is what an agent needs to act safely. It omits any statement of what a successful result contains, though with no output schema that gap is minor.

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 100%, so the schema already documents all four parameters, including the op_key retry contract and revoke_others' effects. The description restates those semantics in prose rather than adding format or edge-case detail the schema lacks, so the baseline 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?

The description states a specific verb and resource — exchanging a single-use recovery code — and pins the 15-minute window, so the operation is unambiguous. It never names the sibling request_recovery to differentiate the two, so it falls short of the top band.

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?

It explains the retry rule (reuse op_key for the original result) and the effect of revoke_others, which is useful operational guidance. However, it never states when to choose this tool over the obvious alternative request_recovery, nor any prerequisite for obtaining the code.

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