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

With no annotations present, the description carries the full behavioral burden and does well: it discloses a per-call price of $0.05 USDC via x402, the exact payment field (_meta["x402/payment"]), and a free sample escape hatch. It also describes what each observation contains (change vs previous, 7-observation mean, z-score, anomaly flag). It omits error behavior, rate limits and what /tables returns, keeping it below 5.

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 lead question front-loads the value proposition, followed by sources, metrics, routes, then payment mechanics in a compact block. Minor filler appears in '(World Signals Pro)' and 'Computed by Lilambd', but almost every clause carries information an agent needs.

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 tool with no annotations, no output schema and a nested free-form params object, the description supplies the missing pieces: data sources, metric semantics, route-to-parameter mapping, and the paid-vs-sample decision. Gaps remain around /tables' parameter set and response shape, which matters since there is no output schema.

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 100%, so baseline is 3, but the description adds real meaning the schema lacks: it maps route /latest to its accepted parameters (table, date, limit, offset), which the generic 'params' object in the schema does not reveal. Only the /tables route's parameters remain undocumented.

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 names a concrete question ('What moved today in world events and tech?') and enumerates the exact data sources: latest-day GDELT events by country and event type, GitHub new repos, Hugging Face trending, and npm/PyPI downloads, plus derived metrics. That is a specific verb-plus-resource statement. It never distinguishes itself from the sibling 'signals', 'rising' or 'pulse' tools, so it stops short of a 5.

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 gives operational guidance for invocation: use route /latest with table/date/limit/offset, or /tables, and set sample=true for a free 3-row preview before paying. It does not say when to prefer this tool over the sibling 'signals' tool or when not to use it at all, so usage is implied rather than fully directed.

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