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

With no annotations, the description carries the full burden and does a lot: it discloses that the response contains specification and partner_offers with EUR prices incl. VAT, mandates that prices be quoted only from partner_offers, and enumerates the link fields (product_url, booking_link, links.web) including the fallback order when each is absent. It does not cover failure modes, empty fitment results, or any auth/rate-limit characteristics.

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?

Purpose and return contents are front-loaded, but the middle section spends several clauses on caps-heavy presentation instructions for product_url/booking_link fallbacks that read more like workflow script than tool definition. The emphasis capitalisation and mixed SK/EN make it denser than necessary.

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 an 8-parameter, unannotated, no-output-schema tool this is substantially complete: it explains what comes back, where prices come from, how the partner is resolved, and what to do when vehicle data is unknown. Remaining gaps are error/empty-result behavior and any note on result freshness.

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 description coverage is 100%, so the baseline is 3, but the description adds real semantics: partner_code is sourced from get_partners, the engine parameters are optional refinements ('voliteľne motor'), and it explicitly rules out VIN/EČV that a naive agent might otherwise try to supply as a free-text parameter.

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 a specific verb and resource in the very first word ('Fitment: nájde batérie...') and scopes it precisely to a concrete vehicle (make, model, year, optionally engine), which tells an agent immediately what the tool produces: technical specification plus real partner offers. It does not, however, explicitly contrast itself with the sibling search_batteries, so the agent must infer the difference from the 'CONKRÉTNEMU VOZIDLU' scoping alone.

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 clear routing rules: partner must be chosen via get_partners (partner_code), and if the customer doesn't know the vehicle parameters, use photo booking (get_partners form_type=booking3). It also states an explicit prohibition ('NEZADÁVAJ VIN ani EČV'), which is valuable negative guidance. It stops short of explicitly naming search_batteries as the alternative for non-fitment lookups.

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