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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds real behavioral context beyond them: Italy-only coverage, the document-oriented return (offers, flyers, weekly price pages), and the relationship that full text comes from fetch. It does not discuss rate limits or result counts, so a 4 rather than 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?

Dense but well front-loaded: trigger first, then scope, then return format, then the sibling hand-off. Every sentence carries information, though the run-on structure of the first sentence makes it slightly harder to scan than it could be.

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 single-parameter search whose output schema documents the return shape, the description supplies everything else an agent needs: geographic scope, query language, example phrasings, and the fetch pairing. Nothing material is missing.

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; the description earns above that by supplying language requirement (Italian), the maxLength constraint (200), and concrete query shapes ('caffè Lavazza a Milano', 'volantino Lidl', 'prezzo pasta') that the terse schema description does not.

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+resource (free-text search over Italian store flyers) and immediately bounds it: no filters, no sorting, Italy only. It also explicitly contrasts with search_flyer_offers and fetch, so the agent can distinguish it from every relevant sibling.

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 an explicit trigger ('when you need citable sources for a free-text question ... no filters or sorting needed') and an explicit exclusion that routes the agent elsewhere ('Sorting by price, a price cap and a choice of chains belong to search_flyer_offers'). This is close to ideal routing guidance.

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