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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered; the description still adds the useful 'reads public data only' scope note. It also compensates for the missing output schema by naming what comes back per product (all-time low/high, rating, test score, link). It stops short of noting rate limits, empty-result behavior, or error modes.

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 tight sentences: purpose and scope first, then return payload, then sibling routing. Every clause carries information, and the return-field list earns its space given there is no output schema.

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?

With no output schema, the description supplies the return shape itself; with 100% parameter coverage, nothing param-related is missing. Safety and scope are covered jointly by annotations and the 'public data only' note, so an agent can call this correctly with no further reading.

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% and the description adds essentially nothing beyond it for page, limit, market, or language. The example query text ('samsung 990 pro 2tb') duplicates the schema's own example, so the baseline of 3 applies.

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?

States a specific verb and resource ('Search the Geizhals price comparison') with market scope (Germany, Austria, EU) and a concrete example query. The enumerated return fields and the explicit hand-off to geizhals_get_product make it unmistakable versus siblings like google_search or trustpilot_get_company_reviews.

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 routes the agent: keyword search here, then geizhals_get_product with a product_id for current shop prices, and geizhals_get_price_history for the trend. That covers both alternatives and the condition that selects each, leaving nothing to inference.

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