Read one contact in full

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

Annotations already cover read-only, idempotent, non-destructive behavior, so the description adds value by disclosing output traits: unmodelled properties are surfaced by name, and free text is fenced so it is not mistaken for server-generated prose. No contradiction with annotations.

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 sentences, immediately front-loaded with the core purpose ("complete card behind an id"), and every phrase carries information. The list of fields and the fencing detail add value without padding.

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-paramter read with rich annotations and an output schema, the description is complete: it specifies the input source, the full scope of the return, and the presentation of free text. No critical calling information appears to be missing.

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 only parameter is id, and its schema description already explains valid origins (list_contacts, search_contacts, etc.) at 100% coverage. The tool description adds no new parameter semantics beyond referring to "an id", 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?

The description states a specific verb and resource ("Read one contact in full") and explains what "full" means: every address, phone number, note, birthday, and names of unmodeled properties. It distinguishes itself from list_contacts and get_contact_photo by emphasizing the complete card rather than a summary or a single artifact.

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 and schema clearly indicate the entry point: an id produced by list_contacts, search_contacts, list_groups, or list_changes. This tells an agent when it can call this tool, though it does not explicitly say when to prefer a sibling like get_contact_photo or search_contacts.

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