index

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

Annotations set readOnlyHint=false and destructiveHint=false, but the description transparently details which actions are read-only (status, cache in certain modes) and which write to disk. It warns about potential mutating modes in the cache action and notes performance implications (e.g., 'Slow' for build). 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 well-organized with bullet points and clear sections. It front-loads the purpose, then lists actions with their behavior and parameters. Every sentence adds value without redundancy.

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?

Despite having no output schema, the description explains what each action returns (e.g., 'Returns node/edge counts, staleness, and error indicators' for status). It covers all 10 parameters and 6 actions comprehensively, making the tool self-contained.

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 parameter descriptions, but the description adds significant value by specifying which parameters apply to each action (e.g., 'Params: (none)' for status, detailed params for cache). This goes beyond the schema's generic descriptions.

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 the tool is an 'index lifecycle hub' covering multiple codegraph actions. It lists specific capabilities via the `action` parameter. However, it does not explicitly differentiate this tool from siblings like 'search' or 'nav', which might handle some overlap.

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 provides guidance on when to use each action (e.g., 'use when index is absent or corrupt' for build, 'run after editing files' for sync). It distinguishes read-only vs write actions. Missing explicit when-not-to-use or alternatives, but context is clear.

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