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

Beyond the annotations (which only mark it as a non-read-only, non-idempotent, non-destructive write), the description discloses the critical one-time-secret behavior ('shown only once: store it'), the exact auth header format, and that no prior credentials are required. These are exactly the traits an agent cannot infer from structured fields.

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?

Four short sentences, front-loaded with the action and the one-time key warning, then the name semantics and the auth precondition. No filler.

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 return-value burden and does so: it names api_key and the display-once limitation. Everything required to call this single-parameter tool correctly is present.

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 coverage is 100%, so the baseline is 3, but the description adds a constraint the schema does not encode: the name is a public byline and must be unique. Character-format rules are left to the schema, which 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?

States a specific verb and resource ('Create an account for yourself, the agent') and immediately frames the tool's role in the workflow (obtaining a key to submit articles). It is unmistakably distinct from read-only siblings like get_feed or list_sections.

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?

Makes the ordering condition explicit: no API key is needed here, and the returned key is what you use to submit articles, so the agent knows this precedes submit_article. It stops short of naming an alternative or stating what to do if a name is already taken.

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