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

Annotations already provide readOnly/openWorld=false/idempotent/non-destructive, and the description adds rich context beyond them: 'Deterministic', 'Touches no third party', 'Nothing is fetched to build it: every fact comes from the headers on your own request or from a file this host already publishes', and processing 'by the same parser and the same index that read a whole file'. This data-provenance and side-effect disclosure is exactly the kind of behavioral detail annotations cannot express.

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 definition is a single dense run-on paragraph that opens with a raw JSON-RPC payload instead of a purpose statement, and the closing example repeats the return list already spelled out earlier. The sibling-path enumeration is an unwieldy wall of parentheticals. Dense with information, but under-structured, redundant, and not front-loaded.

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 zero-argument read-only tool with an output schema and safety annotations, the description covers everything needed: return contents, data sources, determinism, absence of side effects, sibling routing, and a worked example. The only real gap is that the five named sibling paths do not cleanly match the actual sibling-tools list, which could misdirect an agent.

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?

With zero parameters, the rubric baseline is 4. The description confirms 'Takes no arguments' and gives an 'arguments={}' example mapping the empty call to each return value. There is nothing more parameter semantics could convey for an empty 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 states precisely what the tool returns: the caller's user-agent, the class the host books it as, prior-visit status, and the request triaged as a single log line with crawler, operator, category, and address verification. It also distinguishes itself from siblings explicitly ('the part only this server can answer' vs. 'its five siblings answer one other question each'), so an agent can separate it from triage_log, triage_my_request, and the others without opening schemas.

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?

Whe-to-use is explicit: it is the zero-argument tool that answers the caller's own identity/triage, while 'its five siblings answer one other question each about you, same empty arguments,' with alternatives named. The guidance is degraded by a garbled path-to-tool mapping — two entries are labeled 'whoami' and the listed paths do not cleanly correspond to the provided <sibling-tools> list — so an agent could mis-route.

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