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

Annotations already indicate a non-read-only, non-idempotent, non-destructive operation. The description adds valuable behavior beyond that: the need for a CDP-authenticated pending reservation, the one-time capability return, and the security requirement that secret-bearing input/output must not be logged. No contradiction with annotations.

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 two sentences: the first states the broad purpose, the second packs in the prerequisite and a security warning. It is concise and front-loaded, with no wasted words, though the first sentence could be slightly more specific.

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?

Given a mutation tool with no output schema, the description covers the key prerequisite and security constraint, but it is thin on what enrollment actually accomplishes (e.g., enabling autopay, subsequent steps like signing) and how the returned capability is used. In the broader autopay workflow (prepare→enroll→sign), more context would help an agent act correctly.

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%, with both parameters already well-documented (accessToken as a secret credential, enrollmentId as a session ID from prepare). The tool description does not add meaningful parameter-specific semantics beyond echoing the 'never log' constraint already present in the schema, so baseline 3 is appropriate.

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 says 'Manage same-wallet research autopay' which is broad, but the second sentence clarifies this tool performs enrollment ('Enrollment needs...'), and the tool name/title confirm the action. It distinguishes from siblings like revoke/status by mentioning the one-time capability return, though it doesn't explicitly name alternatives.

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 a clear prerequisite: 'Enrollment needs a CDP-authenticated pending reservation,' which tells the agent when to use it (after prepare). It also implies a one-time action with 'capability is returned once.' It doesn't explicitly say when not to use it or name sibling tools, but the condition provides enough context.

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