Create Service Account

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

Beyond the annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), the description discloses authorization requirements, an explicit auth-method exclusion, the fact that no credentials are minted, the separation of role from API key permissions, and a hard quota of 100 service accounts. These are exactly the behavioral traits an agent cannot infer from annotations or schema.

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?

Sentences are dense and front-loaded, leading with the action and constraint before auth and quota details. The one small redundancy is restating that API key permissions are configured separately, which the role parameter description already says.

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 non-idempotent mutation with no output schema, the description still states the returned fields, the auth model, the credential-free nature of the result, and the account quota. An agent has everything needed to decide whether to call it and what to expect.

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 all four parameters (name pattern, role enum, description length, organization source) are already fully documented in the schema. The description echoes the immutability of the name and the stored-role distinction but adds no new syntax or format meaning, 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?

The first sentence gives a specific verb and resource ("Create an organization service account") plus a key constraint ("immutable, unique name"). It also implies the distinction from create-api-key by saying "This creates an identity without credentials," though it never names that sibling explicitly.

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?

Clear preconditions are given: an organization admin, a user session or OAuth, and the exclusion of API keys as a management path. It does not explicitly say when to prefer create-api-key over this tool, but "API key permissions are configured separately" points the agent in that direction.

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