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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds minimal behavioral context beyond the word 'search' and the source ('entities registry'). Since it does not contradict the annotations and the bar is lowered by their presence, a baseline 3 is appropriate.

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 front-loaded sentence that names the verb and resource immediately and appends a useful scope list in parentheses. No wasted words. It earns its place, though it is sparse — a concise but not fully informative definition.

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 search tool with required q, a filter (entity_type), a limit, no enums, and no output schema, the agent is left guessing at the query format, supported type values, and result shape. With 3 parameters and zero schema documentation plus almost no description coverage, the definition is incomplete for reliable 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?

Schema coverage is 0%, so the description must compensate for documenting q, limit, and entity_type, but it does not. The parenthetical list of entity classes indirectly hints at valid entity_type values, which is some value, but q's search format/semantics and limit's behavior are entirely unexplained. With a required q parameter and no schema text, this is a notable gap.

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 ('search') and a specific resource (the entities registry) and lists the covered classes: vessels, operators, owners, flags, ports, refineries, mines. This is clear and concrete. However, it does not distinguish itself from the overlapping specialized siblings query_vessels, query_ports, query_mines, and query_refineries, which weakens the sibling differentiation.

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?

No guidance on when to use query_entities versus the specialized query_vessels/query_ports/query_mines/query_refineries tools. Since the covered type list overlaps directly with those siblings, an agent cannot determine whether to prefer this general registry search or a domain-specific query. There are no exclusions or selection criteria.

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