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

No annotations are supplied, so the description carries the full behavioral burden and handles the most important traits: idempotent re-invocation with no trial reset, the trial quota (100 attempts / 7 days), and the security-relevant return of signing_secret for verifying RunLater-Signature. It omits auth requirements, failure modes, and whether the project can ever be reset or deleted, which keeps it below a 5.

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, each with a distinct job: what is created and its trial terms, the call-once/idempotency rule, and the returned secret's purpose. The critical idempotency warning is front-loaded rather than buried. Minor density in the parenthetical trial figures, but nothing is wasted.

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 zero-parameter provisioning tool with no output schema, the description covers what an agent needs: what gets created, the trial limits, the idempotency contract, and the one returned field that matters downstream. It lacks detail on error conditions or whether other return fields exist, but no material gap blocks a correct 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?

The tool takes zero parameters, so there is no parameter semantics to explain and the baseline is 4. The description spends its space on behavior instead, which is the right allocation.

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 names a specific verb and resource plus scope: 'Create this agent's RunLater project with a free trial (100 delivery attempts, 7 days).' An agent can immediately tell this provisions a project rather than reading one. It stops short of naming the sibling get_project as the read counterpart, so the differentiation is implied by the verb rather than explicit.

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?

'Call once before scheduling' gives a clear ordering constraint and trigger condition, and 'calling again returns the same project and never resets the trial' defers the redundant-call case. It does not point to get_project when an agent only wants to inspect an existing project, which is the one obvious alternative left unaddressed.

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