ck_skill_validate

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

Annotations declare readOnly, idempotent, non-destructive. Description adds behavioral details: output size limit (100KB), that validation uses the skill's frontmatter field, and the two validation paths. No contradictions; description complements 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?

Two well-structured sentences. First sentence states the core purpose and mechanism. Second sentence covers both invocation patterns. No redundant or unclear phrasing. Front-loaded with actionable 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?

Given 4 parameters (1 required), full annotations, and presence of an output schema, the description covers the key behavioral aspects: validation origin, size limit, two modes. Lacks explicit mention of return value, but output schema likely covers that. Sufficient for an agent to select and call 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%, baseline 3. Description adds semantic value: explains that 'output' can be JSON string or plain text (not in schema), clarifies that 'skill_name' makes 'schema' optional, and ties 'project_root' to usage with skill_name. This goes beyond what the schema alone tells the agent.

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?

Description clearly states the action ('Validate skill output against a JSON Schema'), specifies the resource (skill output), and distinguishes two modes (direct schema vs. built-in schema). The verb 'validate' is specific and distinguishes it from sibling tools like ck_validate, which may validate other things.

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?

Explicitly says when to use: after running a skill to enforce typed output. Describes two invocation modes (output+schema or output+skill_name). Does not explicitly state when not to use, but context is clear. No mention of alternatives, but sibling names suggest other validation tools (e.g., ck_validate) exist.

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