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

The description discloses that the estimate is heuristic, approximate, and based on 'symbol-name + text matches' rather than exact analysis. Words like 'coarse' and 'likely touches' warn the agent not to treat the result as ground truth, which is valuable behavioral context beyond the read-only and idempotent 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?

Every sentence earns its place: what the tool produces, when it is used, and how it works. The core purpose is front-loaded and there is no filler or repeated 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?

For a tool with no output schema, the description conveys the essential return concept (coarse file count and layer/repository span) and the decision it informs. It stays somewhat high-level about the exact response shape, but that is consistent with a heuristic pre-flight tool, and the annotations already cover safety and idempotence.

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 coverage is 100%, so the baseline is 3 because the schema already describes all three parameters. The description's mention of 'symbol-name + text matches' hints at how the tool processes input but does not add explicit parameter-level guidance such as formatting, required content, or how to use the optional feedback/projectId fields.

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 opens with 'Pre-flight estimate before graph traversal' and clearly defines the output: a coarse count of touched files plus whether the change spans layers or repositories. It also positions the tool as a decision aid ('Decides single-file edit vs consulting the graph'), which distinguishes it from graph-traversal siblings like ask_codebase and diff_impact.

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 clearly frames when to use the tool: before graph traversal, to decide whether a single-file edit is enough or whether the graph should be consulted. It does not explicitly name sibling tools or list when-not-to-use conditions, but the pre-flight framing and decision role provide sufficient context for an agent to select it appropriately.

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