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 that data is returned 'when available,' implying partial results, but does not mention error handling, authentication, rate limits, or whether the operation is read-only. For a simple enrichment tool, this is a moderate gap.

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, efficient sentence that front-loads the purpose and lists expected output fields. No wasted words, and it reads naturally.

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?

The tool has one parameter, no output schema, and no annotations. The description lists the data fields returned but does not specify the return structure or behavior when the phone is not found (e.g., empty object, error, null). 'When available' hints at partial data but leaves ambiguity. This is a notable gap for an agent to correctly handle results.

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?

Schema coverage is 100% – the schema fully describes the 'phone' parameter with format and example. The description adds no new parameter semantics beyond stating it's a 'known phone number,' which is already implied. Baseline 3 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 states a clear verb-resource pair: 'Enriches a known phone number' with specific data fields (name, email, company, LinkedIn/X profiles, carrier). It distinguishes from siblings like run_email_enrichment (email) and run_phone_enrichment_us (likely US-specific) by focusing on international phone numbers, though it doesn't explicitly name them.

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 known phone number and want associated profile data. It does not explicitly contrast with alternatives like run_phone_enrichment_us, so exclusions are missing. However, the context is clear enough for an agent to select this tool for phone-based enrichment.

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