pattern_lookup

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

No annotations provided, so description must disclose behavior. It only states the basic action, omitting whether the tool is read-only, side effects, output format, or any constraints like requiring a valid project root.

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?

Single sentence is very concise and front-loaded with the main action. However, it sacrifices completeness for brevity; adding a second sentence about output or usage would improve without losing conciseness.

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 tool with 3 params and no output schema or annotations, the description should at least explain expected output, how filtering works, and parameter roles. It only provides a minimal filter action, leaving gaps for correct agent invocation.

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 only 33%, but description adds no parameter-specific detail. It mentions 'by Pk label or keyword' but does not explicitly map to the 'query' parameter, and ignores 'max_chars' and 'project_root' parameters. The description fails to compensate for low schema coverage.

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 (filter), resource (course-index/patterns.md), and method (by Pk label or keyword). It distinguishes from sibling tools like build_course_index or save_course_index, which serve different purposes.

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?

Usage is implied: use when you need to filter patterns. However, no explicit guidance on when to use versus alternatives, nor any prerequisites or exclusions are mentioned.

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