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

The annotations already declare this as a safe, read-only, idempotent, closed-world operation. The description adds valuable context beyond that: it explains the directional semantics of counterparties and states that results include act counts and EUR totals. It does not discuss pagination, rate limits, or edge cases, but with annotations and an output schema present, the bar is lower.

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?

The description is compact and front-loaded: it leads with the core resource and immediately clarifies the directional behavior and returned metrics. Every clause earns its place, with no filler or repetition.

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?

Given an output schema, full parameter schema coverage, and annotations covering safety and idempotency, the description supplies the key missing nuance: how counterparties differ for buyers versus suppliers and what metrics are returned. It could optionally add a brief usage contrast with sibling tools, but nothing critical for correct invocation 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 description coverage is 100%, and both parameters are documented there (afm as a 9-digit ΑΦΜ, limit with max 30 and default 10). The description refers to 'an entity (ΑΦΜ)' but adds no syntax, format, or limit details beyond what the schema already provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 clearly identifies the resource (top counterparties of an entity by ΑΦΜ) and specifies the directional logic: suppliers for buyers, public buyers for suppliers. It also mentions the returned metrics (act counts and EUR totals), so the purpose is concrete. It does not explicitly differentiate itself from siblings such as get_entity or spend_by_cpv, which keeps it from a 5.

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 phrase 'due-diligence view' suggests a use case, and the buyer/supplier distinction implies when the tool is relevant. However, there is no explicit when-to-use guidance, no exclusions, and no named alternatives among siblings like get_entity or spend_by_cpv. Usage is therefore only implied.

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