Per-File Metrics

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

Annotations already mark the tool as read-only and idempotent, and the description ('report') is consistent. However, the description adds no additional behavioral context such as auth requirements, rate limits, or how the returned data is structured. With annotations carrying the load, the description fails to provide extra insight.

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 a single sentence with no wasted words. It is front-loaded with the action verb 'Report'. It prioritizes essential information, though it could optionally mention the response_format options or filtering capabilities for completeness without becoming verbose.

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 has an output schema and full parameter documentation, the description is sufficient for a basic understanding. However, it could be more complete by noting the filtering options (include/exclude extensions, directories) or the fact that it supports both markdown and JSON output. The description is adequate but not thorough.

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?

Since schema_description_coverage is 100%, the schema already documents all parameters. The description only summarizes them ('path, response_format, include/exclude filters') without adding new meaning beyond the schema. This meets the baseline of 3 but does not exceed it.

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 tool's purpose: reporting detailed per-file metrics for a single file or filtered directory. It uses specific verbs ('Report') and identifies the resource ('per-file metrics'). However, it does not explicitly distinguish this tool from siblings like scc_top_files or scc_count_lines, which also report file-level metrics, so it loses some points for differentiation.

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 no explicit guidance on when to use this tool versus its siblings. It mentions filtering but does not explain scenarios where this tool is preferred over alternatives such as scc_by_extension or scc_top_files. The parameter descriptions offer some implicit context, but the tool lacks clear usage recommendations.

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