Feature Validate

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

Beyond the readOnlyHint annotation, the description explains the non-building nature, enumerates the exact failure classes it detects (unknown template, missing/malformed references, scalar-input failures), and discloses the return shape {ok, problems}. It also documents a meaningful limitation, which is useful behavioral context beyond the annotations.

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 description is compact and front-loaded, with each sentence adding distinct value: what it does, what it catches, what it does not catch, and what it returns. There is no repetition of annotations or 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?

With no output schema, the description supplies the return contract ({ok, problems}), the full scope of validation, and the boundary with feature_instantiate. An agent has enough information to call the tool correctly and interpret its result.

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 0%, so the description must compensate, and it does: it names {template, refs, inputs} and maps each to its validation concern—template identity, references, and scalar inputs. It does not specify the exact object shape of refs/inputs, but that is reasonably left to the template being validated.

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 states a specific verb and resource: 'Validate a feature instantiation {template, refs, inputs} WITHOUT building it.' It also distinguishes itself from the sibling feature_instantiate by explicitly noting that geometry-dependent tags are caught there, not here.

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 positions the tool as a 'cheap structural front door' before building, and explicitly tells the agent what it does not catch ('A tag that doesn't resolve against real geometry is caught at feature_instantiate time'). The mention of recipe_validate as a mirror gives an additional routing signal to an analogous sibling.

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