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

Goes well beyond the annotations (which only mark it non-readonly, non-destructive, non-idempotent). It discloses the critical one-time return behavior ('returned only once; Wavelength keeps only a hash'), the lifecycle caveat that the key stops working if you lose owner/admin status, available scopes, and the 10-key cap. This is exactly the behavioral context an agent needs before an irrevocable creation.

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?

Front-loaded with the action, followed by short sentences each carrying a distinct fact (one-time return, persistence, lifecycle, scopes, quota, permissions). Slightly repetitive in re-listing the scopes already present in the enum, but otherwise efficient.

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?

With no output schema, the description carries the burden of explaining the return, and it does so precisely (key shown only once, only a hash retained). Combined with permissions, quota, and scope details, nothing an agent needs to call this correctly is missing.

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 (label, org_id, scopes, expires_in_days) are already documented in the schema. The description restates the scope values, which duplicates the schema enum rather than adding new meaning, 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?

States a specific verb and resource ('Make an organization API key for the Wavelength REST API') and clearly differentiates from siblings like create_organization and revoke_org_api_key. An agent can identify the operation without opening the 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 real context: 'Only an owner or an admin can do this' establishes the permission prerequisite, and 'Up to 10 active keys' signals a quota constraint. It stops short of explicitly naming alternatives (e.g. revoke_org_api_key) or stating when not to use it, so it falls just short of a 5.

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