carrel_index

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

With no annotations, the description must carry the full behavioral burden; it partly does by disclosing the return values (indexed/skipped/pruned counts) and the default root resolution. It never states that desk files themselves are not modified, that `prune` deletes index rows, whether runs are idempotent, or how expensive a full-root build is.

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?

Two short sentences, front-loaded with the action and scope; nothing irrelevant. Minor redundancy in 'under root (default: the whole root)' where the default restates the scope.

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 no-annotation, five-parameter mutation of on-disk index state with no output schema, the description covers the basics (default scope, return counts) but omits safety-relevant context such as what `prune` destroys and cost of a full build.

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 all five parameters are already documented in the schema; the description only restates the default root scope. It adds nothing about how `paths` interacts with `update` or about the `prune`/`ocr` trade-offs beyond the schema strings.

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?

Uses a specific verb pair ('Build or refresh') with a concrete resource ('the desk full-text index') and states the default scope ('the whole root'). This clearly separates it from carrel_search or carrel_pack, though it never names a sibling explicitly.

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?

'Build or refresh' implies a re-runnable setup step that search presumably depends on, so usage is inferable. But there is no explicit when-to-use, no when-not-to-use, and no mention of when to pass `paths`/`update` versus letting it walk the root.

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