contact_by_id

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

No annotations are provided, and the description offers no information about side effects, return values, or required permissions. The description is essentially a label with zero behavioral context.

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 extremely short, but this is under-specification rather than effective conciseness. A single noun phrase does not earn its place as a useful description; it provides no actionable information.

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?

Despite having a schema and output schema, the tool's overall purpose and usage are not adequately explained. The description is too minimal to be considered complete for agent decision-making.

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 description contributes no parameter information, but the input schema thoroughly documents all three parameters, including a detailed enumeration of possible system fields for the 'fields' parameter. Since schema coverage is 100%, the description need not add anything, though it doesn't.

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 'Контакт по номеру' merely restates the tool name in Russian, lacking any verb indicating an action such as retrieving or fetching. It does not differentiate from sibling tools like contact_list or update_contact, leaving the tool's function ambiguous.

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?

There is no guidance on when to use this tool versus alternatives like contact_list or create_contact. It fails to state that this tool is for retrieving a single contact by its identifier.

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