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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds value beyond that by disclosing what the tool reports at a behavioral level: available networks and their per-result cost. With no output schema present, it also implicitly tells the agent what comes back, though it does not describe format, currency, or granularity.

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?

Two sentences, zero waste, with the content statement first and the invocation trigger second. Every sentence earns its place.

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 read-only inventory tool with no output schema, the description is nearly sufficient: it names both the available networks and the cost-per-result dimension of the return. It stops short of describing the response shape (e.g., currency units or per-network fields), which is the only remaining gap given no output schema exists.

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 and the schema is empty at 100% coverage, so there is nothing for the description to clarify. Baseline of 4 applies. No parameter guidance is needed or given.

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 a concrete resource and scope: the networks this server can read posts from, plus per-result cost. It distinguishes this inventory tool from siblings like scrape_posts and estimate_scrape_cost by framing it as a capability-and-price listing rather than an action. It loses a point only because the tool name 'list_scrapers' and the description's 'networks' terminology are not explicitly reconciled.

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 an explicit trigger: call it when the user asks whether you can look at a competitor. That is a clear, actionable usage context. There are no stated exclusions or named alternatives, so it falls short of a full when/when-not/alternatives treatment.

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