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

With no annotations, the description carries the burden and does add real context beyond the schema: it discloses the data provenance (real call logs from the signal_usage database) and the refresh cadence (every Sunday 03:00 UTC), which tells the agent data may be up to a week stale. It also surfaces the cost ($0.007) up front. Gaps remain — no statement that it is strictly read-only, and no indication of auth or payment mechanics.

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 short sentences, front-loaded with the price and the core payload list; nearly every clause earns its place. The price-first ordering is a minor distraction from purpose, but the rest is tight and scannable.

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-parameter tool with no output schema, the description does the necessary work by enumerating the categories of data returned and the freshness window. What is missing is any hint of response shape (sections, keys, size) or behavior when the database has little recent data.

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 tool takes zero parameters, so the baseline is 4. The description correctly implies no inputs are needed and focuses entirely on what the call returns.

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 the specific resource — weekly meta-analytics over APEX signal usage — and enumerates the concrete payloads (buy patterns, co-occurrence, retirement candidates, price recommendations, retention). That clearly separates it from market-data siblings like btc_price_tick or funding_rate. It lacks a leading verb (e.g. 'Returns'), but the noun phrase is unambiguous.

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?

Usage is only implied: an agent can infer it is useful for deciding which signals are popular or dead, but the text never states when to call it versus a sibling, nor any exclusions or prerequisites. No explicit 'use this when' framing is present.

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