billy_update_contact

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

Discloses the confirm-for-execution pattern and dry-run behavior, which adds value beyond the schema. But missing details on what the patch object accepts and what the response returns, especially with no 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, no fluff. Front-loaded with purpose, immediately followed by the most critical usage detail. Every word 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?

Minimal for a mutation tool with nested parameter (patch) and no output schema. Lacks description of return value, permissible patch fields, or prerequisites.

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?

Only the confirm parameter is described in the description, and it mostly restates the schema. The id and patch parameters are left entirely unexplained, despite low schema coverage (33%).

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?

Clear verb+resource: 'Update an existing contact.' Distinct from create and read tools among siblings. The 'WRITE' annotation reinforces its mutating nature.

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?

Explicitly states the confirm:true requirement, which is a crucial usage guideline. However, no guidance on when to use vs. other contact tools (e.g., create vs. update) or alternatives.

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