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

No annotations are provided, so the description carries the burden. It discloses the key behavioral rule of calling as soon as one contact detail is available and highlights the 'light signup' nuance. It doesn't mention side effects or auth, but the core behavior is transparent.

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 two sentences plus a brief parameter instruction, with no filler. It front-loads the main purpose and provides actionable guidance.

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 lead-creation tool with no output schema, the description covers when to use it, what to pass, and the main caveat (one contact detail). It doesn't describe return values, but that's not critical for invocation.

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 already describes all parameters (100% coverage), and the description adds meaning by emphasizing the 'email OR phone' rule and the requirement to pass 'message' with a brief summary. This goes beyond the schema.

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 'Registra a un visitante interesado en contratar un servicio de Cooper', clearly specifying the action (register) and resource (visitor lead). It also distinguishes from siblings by mentioning use cases like 'anotar al user fuera de cobertura' and 'signup ligero antes de cuenta completa'.

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?

Provides explicit timing guidance ('Llamar APENAS se tenga UN dato de contacto... no esperar a tener ambos') and clear use cases (outside coverage, light signup). It does not explicitly name alternative tools, but the context strongly implies when this tool is appropriate.

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