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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld). The description adds genuinely non-structured behavior: anchor/prefix matching semantics, a hard cap of 20 results, and a cost model billed per record found with a minimum of 1, which an agent needs before calling.

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?

A single dense sentence-pair that front-loads the matching semantics, then the parameter requirement, then the result cap and cost. Every clause carries information an agent needs; no filler.

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?

With no output schema, the description still conveys cardinality (max 20) and cost, and annotations carry safety. Combined with 100% schema coverage, an agent has enough to invoke correctly; only explicit sibling routing 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 lifts this by clarifying that matching is from the start of the string, and reinforces the 'at least one param' rule that the schema does not enforce. It stops at 4 because it doesn't add per-parameter nuance beyond the already-detailed schema strings.

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 ('Поиск организаций') and the exact matching fields (name prefix, email, region), and explicitly rules out full-text search by specifying prefix/anchor matching. It does not name a sibling (e.g., org_lookup, new_organizations) to disambiguate, so it stops short of 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?

Gives a real usage constraint — at least one parameter is required and parameters can be combined — which is clear operating context. However, it never says when to prefer this over org_lookup or the check_* tools, so alternative-selection guidance is absent.

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