check_acceptance_criterion

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

Annotations already indicate this is a destructive, non-idempotent, open-world write operation. The description adds valuable context beyond annotations: it specifies the exact transformation (- [ ] → - [x]), describes error conditions (story not found, criterion not found, already checked), and mentions the return structure. This enhances behavioral understanding without contradicting 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 perfectly front-loaded with the core purpose in the first sentence, followed by essential usage details and error conditions. Every sentence earns its place with zero wasted words, making it highly efficient for agent comprehension.

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 the tool's complexity (destructive mutation with multiple parameters) and lack of output schema, the description does well by explaining the return structure and error conditions. However, it could be more complete by mentioning what happens to the story file (e.g., whether it's saved automatically) or providing examples of story_id format beyond the schema's 'e.g. STORY-047'.

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%, providing full parameter documentation. The description adds marginal value by reinforcing the mutual exclusivity of criterion_index and criterion_text and emphasizing that exactly one must be provided. However, it doesn't provide additional semantic context beyond what's already in the schema descriptions.

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 clearly states the specific action ('Mark a single acceptance criterion as checked'), the resource ('in a story file'), and the transformation ('- [ ] → - [x]'). It distinguishes from siblings like 'set_acceptance_criteria' (which sets multiple criteria) by focusing on checking a single criterion.

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 provides clear context for when to use this tool (to check a single acceptance criterion) and specifies that exactly one identifier (criterion_index or criterion_text) must be provided. However, it doesn't explicitly mention when NOT to use it or name alternatives like 'complete_story' or 'set_story_status' for broader story completion.

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