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

With no annotations, the description carries the full burden and does so: whole-batch pre-validation, 400 `invalid_request` naming `subjects[i]`, 413 `payload_too_large` above 50 subjects, inline `{ok:false,error}` partial-failure semantics, rate-limit accounting (one unit per subject, whole-batch 429 refusal charging nothing beyond the first unit), and per-tier budgets.

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?

Front-loads the core purpose, then organizes the rest under clear Inputs / Returns / Cost / Latency headings. It is dense but every section carries actionable information for a tool with no annotations and no output schema; the cost paragraph is the only mildly verbose stretch.

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?

No output schema and no annotations exist, so the description must supply return shape and error behavior — it does both (`count`, `results[]`, per-entry `{ok, subject, ...verdict}` plus `receipt_id`/`signature`). Errors, cost limits, and latency are all covered, leaving nothing an agent needs in order to call it correctly.

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 50% (only `receipt` is documented in-schema). The description compensates by defining the accepted subject formats — 1-50 IPs, domains, ASNs (AS####) or cert hashes — which the schema lacks entirely, and clarifies the receipt flag's signing/persistence behavior. It stops short of 5 only because exact hash/ASN formats remain loosely specified.

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?

Opens with a specific verb+resource and scope: 'Batch form of `ghostroute_check`: one verdict per subject, aligned to input order.' This immediately distinguishes it from the single-subject sibling `ghostroute_check` and tells the agent exactly what it produces and how results are ordered.

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 states 'Use this tool when: You need routing-integrity / sovereignty verdicts for many endpoints at once,' which frames the batch-vs-single choice. It does not spell out a negative condition ('do not use for a single subject; use ghostroute_check'), so it falls just short of a 5.

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