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

No annotations exist, so the description carries the full burden. It discloses non-obvious behavior: wall-clock interpretation in a timezone, recurring plan semantics, and the creator_key's authorization role for locking. While it doesn't enumerate every side effect (e.g., email sends), it provides substantial behavioral context beyond the name.

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 sentences, densely packed but every clause earns its place. The most important info (purpose and return values) is front-loaded, with timezone and recurring rules following naturally. No fluff or redundancy.

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 tool with 11 parameters and no output schema, the description covers the key return values, the creator_key's purpose, and tricky recurrence/timezone behavior. It doesn't address every edge case or error condition, but it provides a solid mental model for a plan-creation tool. The schema handles parameter details, leaving the description to focus on usage nuance.

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%, which sets a baseline of 3. The description adds valuable semantics for the complex 'days' parameter (date vs weekday vs daily vs monthly rules) and clarifies timezone handling. It reinforces and extends the schema's parameter docs, justifying an above-baseline score.

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 opens with a specific verb-resource pair ('Create a Whenna plan') and clarifies the output (shareable link, creator_key). It clearly distinguishes itself from siblings like whenna_best_times or whenna_lock_time by focusing on plan creation.

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 implies when to use the tool (when you need to create a plan) but does not explicitly reference alternatives or exclusions. No guidance is given on when to prefer this over whenna_best_times or whenna_get_plan, so it falls short of explicit usage direction.

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