timeline_edit_fillet

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

With no annotations, the description carries the full behavioral burden and does so well: it discloses atomic application of keys, rollback and FUSION_API_ERROR on feature error, details.reverted, the allow_errors override, INVALID_PARAMS behavior, and the 'nothing to change' failure case.

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?

The purpose is front-loaded and the example plus return/error details are relevant. The description is dense and could be easier to scan if split into bullets, but it contains no obvious filler.

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?

Given no annotations and no output schema, the description supplies the missing return shape, error semantics, rollback behavior, and allow_errors behavior. Combined with full schema parameter coverage, an agent has enough context to call the tool correctly.

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 documents feature, radius, units, and allow_errors. The description adds useful behavioral context around applying all keys together and error handling, but does not materially deepen individual parameter meanings beyond the schema.

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 first sentence states a specific verb and resource: set the radius of every constant-radius edge set of an existing fillet. This clearly distinguishes it from fillet creation tools such as feature_fillet and from editing other feature types.

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 makes clear that the tool applies to an existing fillet and gives a short example, but it does not explicitly state when to use this versus feature_fillet or feature_rule_fillet. Usage is implied rather than fully routed.

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