index

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

Annotations provide idempotentHint=true, readOnlyHint=false, destructiveHint=false. The description adds behavioral context: it creates a .codebaxing/ folder, describes mode-specific behaviors (incremental vs full vs load-only), and implies file system modifications. No contradiction with 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 extremely concise: two short sentences plus a three-line bullet list for modes. Every sentence adds distinct value (purpose, required status, mode variants, side effect). Front-loaded with the core purpose.

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 4 parameters (all documented in schema), no output schema, and moderate complexity (tool changes filesystem), the description covers the critical aspects: purpose, required-first-step context, mode options, and a key side effect (folder creation). It does not describe return values or error conditions, but for a setup/indexing tool this is acceptable. A perfect score would require mention of typical output or behavior on failure.

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% with 4 parameters. The description expands on the 'mode' parameter by explaining each enum value's purpose, which adds value beyond the schema's terse 'Indexing mode'. However, it does not add any new information for path, embedding_model, or file_extensions (their schema descriptions already clear). Baseline 3 is appropriate.

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 'Index a codebase for semantic search' and identifies it as 'REQUIRED FIRST STEP', which strongly distinguishes it from sibling tools like search, stats, and clean. The verb 'index' and resource 'codebase' are precise.

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 says 'REQUIRED FIRST STEP', indicating it must be run before dependent operations. It details three modes (auto, full, load-only) and when each is appropriate. However, it does not explicitly state when NOT to use the tool or list alternatives, though context implies alternatives are the other sibling tools.

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