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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so the safety profile is covered. The description adds genuinely non-structured context: results are either cross-shop product comparisons or single-shop offers for unmatched items, prices include VAT, and the user should be given each result's url. It doesn't cover rate limits or pagination depth beyond the limit field, so it stops short of a 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?

Front-loaded with purpose and trigger in the opening sentences, then progressively adds operational detail. It is long and dense, packing five distinct directives into the same paragraph, but virtually every clause provides actionable information rather than filler.

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 exists, yet the description explains the two possible result shapes (multi-shop products vs single-shop offers) and how to surface them (give each result's url). Combined with the sibling routing and parameter guidance, an agent has everything needed to call and present results 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 100%, so the baseline is 3, but the description adds meaning beyond the schema: it warns against putting prices in query, directs budgets to max_price_eur, and conditions the country parameter on user ambiguity. This is real semantic guidance layered on top of fully documented fields.

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 precise verb (search) and resource (products and prices across shops), names the exact underlying services (pricebee.lt/.lv/.ee), and distinguishes itself from get_product, which is explicitly called out as listing a product's shops. An agent can tell what this does and how it differs from siblings without opening any schema.

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?

Gives explicit trigger conditions ('when someone wants to buy something, compare prices or find where a product is cheapest'), operational advice ('ask for the country if it isn't clear', 'put a budget in max_price_eur, not in the query'), and routes to alternatives (get_product, price_overview, search_url) with the condition that selects each.

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