Info Contact

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

No annotations are provided, so the description carries the full burden of disclosure. 'Fetch details' clearly indicates a read-only operation, but it does not describe the return format, authentication needs, or potential errors. The behavior is adequately transparent for a simple lookup, but richer context is missing.

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 a single, front-loaded sentence that directly states the action and target. There is no redundant or filler content, making it highly concise and well-structured.

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 tool with one parameter and no output schema, the description provides sufficient information to select and invoke it correctly: it names the resource type and the required identifier. It would benefit from mentioning the expected return format, but the low complexity reduces the need for more.

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 schema only provides a parameter name 'contact_id' with 0% description coverage. The tool description compensates by clarifying it is the 'Subreg contact id', adding meaning beyond the schema. It does not specify format or examples, so a 4 is 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 uses the specific verb 'Fetch details' and identifies the resource as 'a contact object by its Subreg contact id', clearly distinguishing it from sibling tools like contacts_list (list), create_contact, and update_contact. The scope is unambiguous.

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 usage when you have a Subreg contact id and need full contact details, but it does not explicitly state when not to use it or mention alternatives such as contacts_list for listing all contacts. The context is clear but exclusions and alternatives are absent.

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