Update Step

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

Annotations already signal that this is neither read-only nor destructive. The description adds that the operation modifies step content or completion status, but does not disclose side effects, partial-update behavior, or response details. This is adequate but not rich behavioral context.

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?

Two short, front-loaded sentences with no filler. It states the action and resource first, then gives the concrete use case, and does not repeat schema information.

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 simple, non-destructive update tool with fully documented parameters and annotations, the description plus schema is mostly complete. It could be improved by noting that at least one of content or completed should be provided, and by explaining what the caller should expect in the response.

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 input schema fully documents all five parameters. The description only loosely maps 'description or completion status' to the content and completed parameters, adding no new parameter-level detail.

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 ('Update'), a specific resource ('to-do step'), and the exact scopes ('description or completion status'). This clearly distinguishes the tool from siblings like fizzy_create_step, fizzy_delete_step, and fizzy_get_step.

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 gives explicit usage guidance: 'Use this to mark steps as complete/incomplete or edit their descriptions.' It does not mention alternatives or exclusions, but the resource scope is clear enough that an agent can select it over update_card or other mutation tools.

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