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

Read-only and non-destructive annotations already cover safety. The description adds valuable behavioral context beyond annotations: 'Opaque cursor pagination' warns the agent that pagination is required and cursor-based, and the row-granularity note prevents assuming the data concerns people. No mention of rate limits or auth, but annotations reduce the burden.

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?

Four short sentences, each earning its place: core purpose, row granularity, pagination behavior, and the key sibling alternative. The most important 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?

Given the 100% schema coverage and safety annotations, the description covers the essential non-obvious aspects: pagination and the correct single-lookup alternative. Without an output schema, it could say a bit more about the result shape, but 'Companies that currently match' adequately conveys the return type.

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%, so the schema fully documents kind, emtak, limit, county, and cursor. The description does not add semantic detail beyond the schema—it even omits the distress_high/distress_moderate distinction by saying only 'distress'—so it provides minimal additional parameter value.

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 states the resource: companies that currently match one register signal, and enumerates the signal types. It also differentiates from the sibling check_counterparty by implication, though it lacks an explicit imperative verb like 'list' or 'search'.

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?

It explicitly names check_counterparty as the alternative for a single known registry code, which tells the agent when not to use this tool. Context about row granularity ('each row is a company, not a person') also helps avoid misuse, but no broader exclusions for other siblings are given.

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