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), and the description adds real behavior: accent- and case-insensitive matching plus a fuzzy 'closest names' return. It doesn't state what happens on zero matches or whether results are ranked by score, which keeps it 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?

Three tight clauses: the core action first, the routing condition and alternatives second, the matching/return behavior last. No filler, and the most decision-relevant information is front-loaded.

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 simple 3-parameter read tool with full schema coverage and an output schema, the description supplies the routing rationale and matching semantics an agent needs to invoke it correctly. 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% and each parameter (kind enum, name, limit) is documented in the schema. The description reinforces accent/case insensitivity but adds no syntax or semantics for limit or the buyer/supplier/both enum beyond what the schema already says, so the baseline 3 applies.

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 and resource (resolve a Greek buyer/supplier name to its ΑΦΜ), and explicitly distinguishes itself from get_entity, entity_counterparties and the afm filters which take the 9-digit number. An agent can tell exactly which tool to pick without opening a 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 the explicit trigger ('for when you have a name but no ΑΦΜ') and names the alternative tools and their precondition (they need the 9-digit number). This is the when/when-not/alternatives pattern fully realized.

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