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

Annotations already declare the non-read-only, non-destructive, non-idempotent profile; the description adds real value by explaining that publish defaults to a draft and that the owning service validates the definition on submit. It does not warn that repeated calls create additional versions (relevant given idempotentHint=false), which is the main behavioral gap.

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?

A single tight paragraph with the existing-vs-new distinction front-loaded and the actionable guidance (schema tool, publish flag, alternative tool) in descending order of importance. The parenthetical aside is the only mildly interruptive element.

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 an output schema present, the description needn't explain returns, and it covers prerequisites, validation, draft-vs-publish, and the sibling alternative. What remains unstated is version lineage (whether the new version inherits the prior definition) and the consequence of calling it repeatedly.

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 the schema already explains publish, definition, and schedule_id thoroughly. The description only restates the publish=true behavior and the definition-authoring route, adding little beyond the structured fields; 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?

The description gives a specific verb and resource ('add a new version to an EXISTING schedule') and explicitly scopes the operation by schedule_id. It also names the sibling it is not (create_schedule for brand-new schedules), so an agent can separate it from create_schedule and the publish_* family.

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?

It states the prerequisite (an existing schedule_id) and routes brand-new schedules to create_schedule, and it points at get_schedule_definition_schema for authoring. It stops short of saying how this differs from using publish_schedule or create_schedule_version-style flows when only activation is desired, so it is clear but not exhaustive.

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