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

With no annotations, the description carries the full burden and does well: it discloses cost (free), that no account or email is required, that the key is returned exactly once and must be persisted, and the exact header format for use. It does not cover whether a repeat call issues a new key or invalidates the old one, nor any rate limiting, which is the main remaining unknown for a mutation-ish bootstrap call.

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?

Three short sentences ordered by what the agent needs: what it gets, whether to call it, then what to do with the result. No filler and the critical 'key is shown once' warning is not buried.

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?

There is no output schema, so the description must explain the return value, and it does ('the reply carries the key once'). For a two-parameter bootstrap tool that is nearly complete; only error and re-invocation behavior are left unspecified.

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 'name' and 'purpose' are already documented as an agent name and an optional description. The description adds nothing about these fields, which is acceptable given the schema does the work, 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 ('Get a free API key') plus the key qualifier that differentiates it from every sibling: it is a one-time bootstrap call, not a search or reporting tool. An agent can place it in the workflow 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 an explicit precondition ('use it only if your server config has no Lodestar key'), which is effectively a when-not-to-use rule, and then names the follow-up tools (search, get_lesson, report_outcome) to use after the key is installed. Both the decision and the next step are spelled out.

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