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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful detail beyond those flags: financial figures are kept separate with as-of dates, contact points are deliberately withheld, and same_as links are based on shared CRD/CIK/EIN identifiers. This is valuable behavioral context for an agent.

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 dense, front-loaded with 'full card', and organizes a long list of return sections with commas. The opening phrase restates the title somewhat, but overall the length is justified by the amount of content the tool returns.

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 one-parameter read tool with no output schema, the description inventories the response sections and explicitly notes an important omission (contact points). The small mismatch between the description's ID scope and the schema's accepted ID scope is a minor gap, but an agent can still invoke and interpret the result correctly.

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?

The single parameter dfx_id is fully documented in the schema with 100% coverage, listing all accepted ID prefixes. The description only adds 'Accepts dfx:fo: ids', which is narrower than the schema's broader list and adds no new meaning, so the schema carries the semantic weight.

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 verb-resource pair: 'full card for one family office' and enumerates the returned content (profile, AUM/RAUM/13F, people, investments, relationships, events, links). It is specific, but it does not explicitly differentiate itself from sibling get_* or search_family_offices tools beyond the singular 'one' and the ID hint.

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 description implies when to use the tool: when you have a known DFX ID and want the complete family-office record. It also gives an exclusion ('Contact points are withheld over MCP'), but it never names alternatives such as search_family_offices or search_family_office_investments, nor states when those should be preferred.

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