get_contacts

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

No annotations are provided, so the description carries the full burden. It mentions the return format ('Contact information as JSON'), which is helpful, but lacks critical behavioral details: it doesn't specify if this is a read-only operation (implied but not stated), whether it requires permissions, how errors are handled, or if there are rate limits. The description is minimal and misses key operational 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 appropriately sized and front-loaded: the first sentence states the purpose, followed by structured 'Args' and 'Returns' sections. There's no wasted text, though the formatting could be slightly more polished (e.g., using markdown). Every sentence earns its place.

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?

Given the tool's low complexity (1 parameter, no nested objects) and the presence of an output schema (which handles return values), the description is moderately complete. It covers the basic purpose and parameter semantics but lacks behavioral context (e.g., safety, permissions) that would be important for a tool interacting with device contacts. With no annotations, it should do more to explain operational aspects.

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 adds significant value beyond the input schema, which has 0% description coverage. It explains the 'number' parameter's purpose: 'Phone number to search for, or "*" to get all contacts (default)'. This clarifies the semantics and default behavior, compensating well for the schema's lack of documentation. With only one parameter, this is sufficient.

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 tool's purpose: 'Get all contacts or a specific contact by phone number'. It specifies the verb ('Get') and resource ('contacts'), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'insert_contact' or 'delete_contact' beyond the basic action.

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 through the parameter explanation: use '*' for all contacts or a specific phone number for a single contact. However, it doesn't provide explicit guidance on when to choose this tool over alternatives like 'insert_contact' or 'delete_contact', nor does it mention any prerequisites or exclusions.

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