Map the codebase

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

Annotations already declare readOnlyHint=true (safe read). The description adds behavioral details: recursive mapping, regex-based symbol extraction (with capping), and that results are ordered 'worst first' for split candidates. It doesn't mention performance implications or recursion depth limits, but it sufficiently goes beyond the 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 two sentences, each packed with valuable information. The first sentence covers the core mapping functionality and outputs, the second details the optional symbols feature. No unnecessary words; every phrase earns its place.

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 4 parameters and no output schema, the description gives a good high-level overview but lacks specifics like the cap value for symbols, performance implications, or the exact structure of the returned data. While 'worst first' clarifies ordering, more detail on output format would improve completeness.

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 low (25%) with only 'symbols' having a description. The description compensates by explaining the role of splitBytes and splitLines ('split thresholds (lines/bytes)') and that symbols:true triggers per-file symbol lists. However, the 'project' parameter is only implicitly defined as 'the project's codeLocation', lacking precise meaning. This provides some added value but not full 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?

The description clearly states that the tool recursively maps the codebase, reports total file count and bytes, counts by extension, and identifies files exceeding split thresholds as candidates. It also explains the optional symbol extraction. This distinguishes it from siblings like list_code_files (which likely lists files) or suggest_file_split (which suggests specific splits).

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 explicitly states the usefulness: 'for spotting oversized modules to decompose' and 'a lightweight symbol map for navigation.' While it doesn't explicitly name alternatives or state when not to use, the context of siblings like list_code_files and read_code_file is implied. It provides clear usage guidance without being exhaustive.

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