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

The annotations already cover the safety profile (read-only, idempotent, non-destructive, closed-world), so the description's real contribution is disclosing what the record contains; with no output schema, the list of returned facets is genuinely useful behavioral context. It stops short of noting error behavior (e.g., what happens for an unknown contact_id).

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 compact sentence with no filler; the record scope is front-loaded and every clause names a distinct returned facet.

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 simple, annotated, single-parameter read tool, the definition is nearly complete: safety is covered by annotations, the parameter by the schema, and return content by the description in lieu of an output schema. Minor gaps are error handling and pagination/size expectations.

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?

There is a single parameter with 100% schema description coverage ('contact_id from list_contacts or list_leads'), so the schema already does the heavy lifting. The description adds nothing about the parameter, making the baseline 3 appropriate.

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 states a specific verb and resource ('One Directory record in full') and enumerates the returned facets (contact details, status, services, terms, additional contacts), which clearly separates it from list_contacts. However it never names a sibling explicitly to sharpen the get-vs-list distinction.

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?

Usage is only implied: 'one record in full' hints at fetching a single contact's complete details, but there is no explicit when-to-use or when-not-to-use guidance and no mention of the obvious alternative list_contacts.

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