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), so the bar is lower. The description adds real context beyond them: which principal is scoped ('authenticated user's'), the default-first ordering, and the tax-status taxonomy. It omits pagination behavior, but that is already documented per-parameter in the schema.

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?

Two tightly packed sentences with zero filler; scope, ordering, return fields, and the cross-tool linkage are all front-loaded. Nothing repeats the title or name.

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 carries the return-value burden, and it does partially: default-first ordering, the entity-type examples, and the tax-status enum values. It does not describe the full entity record (ids, names, nesting), so an agent gets the essentials but not the complete response shape.

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% with only page and per_page, both fully described in the schema (defaults and max included). The description adds no syntax or semantic detail about these parameters, 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?

Specific verb+resource ('List the authenticated user's investing entities') with a parenthetical enumerating the concrete kinds (personal accounts, LLCs, trusts, retirement accounts). It also states the ordering rule (default entity first) and the per-row payload (tax status), so an agent knows exactly what it gets. No sibling tool competes for this resource, so there is nothing to confuse it with.

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?

The closing sentence names the downstream consumers explicitly: 'Entity ids feed the entity filter on list_transactions and list_companies,' which tells the agent why and when it needs this call. There is no when-not-to-use or exclusion, and no mention of prerequisites, so it falls short of a 5.

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