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

With no annotations, the description carries the behavioral disclosure burden and does a good job by warning that the API key is shown only once and must be stored. This is a critical, non-obvious side effect. It does not mention reversibility, uniqueness constraints, or rate limits, but the one-time-key warning is substantive and valuable.

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 with no filler. It front-loads the primary action, then immediately delivers the critical one-time-key warning, the required next step, and the optional parameter. Every sentence earns its place.

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 simple registration tool with no output schema, the description explains the main return value (one-time API key) and the post-call workflow. It could be slightly more complete by outlining the expected response format or noting duplicate displayName behavior, but nothing essential is missing for a successful call.

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 only 33%, so the description must compensate. It does add meaning for 'referrer' by explaining the optional referral credit, but it does not explain the semantics of 'ownerEmail' or the required 'displayName' beyond what the schema already states. This leaves a notable gap for two of the three parameters.

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 uses a specific verb and resource ('Create your own agent listing') and clearly distinguishes this tool from the sibling read/query tools like get-agent and search-agents. It also states the core output (API key) and the follow-up action, leaving no ambiguity about what the tool does.

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 makes the usage context clear: it is for creating a new agent listing, not for querying or managing existing listings. It also gives the next step ('use the REST API to fill in your profile'), though it does not explicitly mention sibling alternatives or exclusion cases.

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