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

Annotations already cover read-only and idempotent behavior; the description adds that the call requires no arguments, returns per-row crawler/blocking-cost data, and exposes all valid filter values. However, the embedded whoami JSON-RPC payload is confusing and no pagination/ordering behavior is disclosed, so the added behavioral context is only partial.

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 core description is brief, but front-loading a full JSON-RPC payload for whoami before describing list_crawlers is distracting and does not earn its place. The actual tool purpose appears only after the embedded call, making the structure confusing rather than concise.

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 read-only list tool with all optional parameters, the description covers the output shape (crawler identity + blocking cost), zero-argument invocation, and filter value discoverability. Missing details like result ordering, pagination behavior, and how filters combine are not addressed, but the annotations and schema cover much of the safety and parameter context.

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 the baseline is 3 and the schema carries parameter documentation. The description adds a concrete example (category='ai-training', limit=20) and hints that valid filter values are discoverable from the reply, which is helpful but not substantial beyond the schema.

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 positions the tool as 'the index, filtered or whole' and specifies that each row identifies a crawler and its blocking cost, which clearly conveys a listing/filtering purpose. It does not explicitly name sibling tools or edge cases, but it is unambiguous enough to separate from a single-record lookup.

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?

It explicitly says 'FIRST CALL, needs nothing', signaling this is a safe zero-parameter starting point, and notes that the reply lists every valid filter value, so an agent knows to use it for filter discovery. It does not state when to prefer lookup_crawler or whoami instead, so it stops short of a full routing rule.

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