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

With no annotations, the description carries the full burden. It discloses the four-layer pipeline, ~60 second latency, and the fact that it handles JS-heavy sites. This adds meaningful behavioral context, though it could mention idempotency or error behavior.

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 sentences, front-loaded with the primary action, and every sentence provides useful context (when to use, pipeline, timing, outcome). No unnecessary words or repetition.

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 lacking annotations and an output schema, the description covers purpose, usage, process, duration, and post-condition. It doesn't describe return values or error handling, but for a single-parameter tool this is mostly complete and actionable.

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?

The schema already covers the only parameter 'url' with a clear description and example. The tool description adds context about the URL's role in indexing and JS-rendered sites, but doesn't add new formatting or semantic details beyond the schema, so baseline 3 applies.

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 indexes a website so it can be queried with ask_site. It uses a specific verb+resource construction and distinguishes itself from siblings like list_sites and ask_site.

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?

Explicitly says 'Use this when the site is not yet in list_sites' and contrasts with web_fetch for JS-rendered pages. Also implies ask_site is for querying after indexing, providing clear when-to-use guidance.

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