Search purchase bills

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavior beyond that: passing bill_id returns a single bill in full with its lines, while the normal search filters by period, supplier, or number. It does not detail pagination or result shape, but those are partially handled by the schema.

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 short sentences carry all essential information, starting with the tool's main function and then the special bill_id behavior. There is no filler, no repetition of the title, and no unnecessary detail.

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 read-only search tool with no required parameters, the description plus schema covers the main invocation paths: list search by period/supplier/number and single-bill retrieval by bill_id. Minor gaps remain around how response_format=detailed interacts with bill_id and the lack of output-shape or error notes, but these are not blocking for correct selection and basic invocation.

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 schema documents page, limit, number, bill_id, and response_format; the description supplies semantic grouping for the five undocumented parameters: date_from/date_to as 'period', supplier_eik/supplier_name/supplier_vat_number as 'supplier', and 'number'. This adds real meaning beyond the raw schema, though it stops short of explaining exact-match vs partial-match behavior.

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 uses a specific verb ('Find') and a clear resource ('purchase documents'), reinforced with Bulgarian equivalents, and explicitly names the search dimensions: period, supplier, and number. It also explains the bill_id path for fetching one bill in full with lines, distinguishing this from sales-invoice siblings like nula_search_invoices.

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?

The description makes the tool's context clear: this is the purchase-bill search tool, and the bill_id mode is stated. However, it never names an alternative such as nula_search_invoices or says when not to use this tool, so the agent must infer the boundary from the word 'purchase'. No exclusions or alternative routing are provided.

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