reindex_changed_files

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

With no annotations, the description carries the full burden. It usefully discloses the mechanism (Merkle trees) and that behavior branches on the files parameter, which is real context. However, it omits permissions/auth needs, how deletions or renames are handled, and whether the operation is safe to repeat — notable gaps for a state-mutating index tool.

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?

Three short sentences, front-loaded with the core verb and scope, then mechanism, then comparative value. '(fast)' is slightly redundant against the closing sentence, but overall little waste.

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?

No output schema or annotations exist, so the description must stand alone; it covers what the tool does and its two modes but says nothing about return values, progress/status reporting (a sibling get_index_status exists), or error conditions on a bad path. Adequate but with clear gaps for a 2-param stateful tool.

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 100%, so both parameters are already documented, including that files is optional and triggers auto-detection. The description reinforces the mode switch but adds no syntax, format, or path-relative detail beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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?

States a specific verb (re-index) and scoped resource (only changed files), and explicitly frames itself against the full-reindex alternative with 'Much faster than full re-index.' An agent can distinguish it from index_codebase without opening a schema.

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 makes clear when to prefer this over a full re-index and describes the two operating modes (auto-detect vs explicit files). It does not name the sibling (index_codebase) directly or state when a full re-index is required instead, so it falls short of explicit alternative routing.

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