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

The annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful behavior beyond that by disclosing the sorting order ('largest first') and that counterparty names are resolved, though it says nothing about pagination, limits, or required permissions.

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 a single front-loaded sentence with little wasted text. The vague phrase 'within one income lens' is the main weakness, but the statement is efficiently structured.

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?

Because an output schema exists, the description need not explain return values, and annotations cover the safe-read profile. However, for a four-parameter analytics tool with only 25% schema description coverage, the description leaves key input semantics and sibling distinctions unresolved.

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 only 25% across four parameters, so the description needs to compensate and largely does not. It references a company and an 'income lens' but does not explain companyId's UUID wrapper, the dateFrom/dateTo range, or the INCOME_CATEGORY enum values.

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 uses a specific verb and resource: it lists who paid a company and says results are sorted largest first with resolved counterparty names. The phrase 'within one income lens' is somewhat opaque, and it does not explicitly distinguish itself from siblings like get_income_by_category or spend_get_spend_by_payee.

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 does not state when to use this tool instead of the closely related get_income_by_category or spend_get_spend_by_payee tools. The payer-breakdown use case is implied by the description, but there are no explicit selection criteria, exclusions, or alternatives.

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