status

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

No annotations are provided, so the description carries the full behavioral burden. It implies a passive inspection by listing only statistics, but never states it is side-effect-free, does not say what happens when no index exists (error vs empty stats), and mentions no permissions or cost. Adequate but thin for an unannotated 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?

Two tight sentences with zero waste; the statistics list comes first and the usage guidance second. Front-loaded and appropriately sized for the tool's simplicity.

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?

With no output schema, enumerating the returned statistics is exactly the right compensation, and it covers the 1-param schema adequately. The only gap is undefined behavior when the index is absent, which an agent would likely want to know for a pre-flight check 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?

Only one parameter (project_root) and schema coverage is 100%, so the schema already documents its meaning and default. The description adds nothing about path resolution or the working-directory default, making this the baseline 3.

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 and resource ('Report index statistics') and enumerates the exact contents (symbol count, byte size, embedding presence, last-update timestamp), so an agent knows precisely what comes back. It does not explicitly contrast itself with the similarly-named 'index'/'update' siblings, but the described payload is distinctive enough.

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?

Gives a clear use condition: 'confirm an index exists and is fresh before running search-shaped tools.' This is genuine routing guidance. It stops short of naming alternatives or stating when not to use it (e.g., after running index/update).

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