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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=true), and the description adds a real behavioral fact beyond them: 3 credits charged only on success. It does not mention authentication requirements or rate limiting, but for a read-only lookup this is close to complete.

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?

Front-loaded with purpose, then returns, then usage, then inputs, then cost — a sensible order. The returned-field enumeration is long but earns its place because no output schema exists. Minor redundancy between the 'find/enrich' framing and the field list keeps it short of perfect.

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?

With no output schema, the description supplies the return shape, and with no required parameters it supplies the input combinations. Cost semantics, alternatives, and the read-only posture are all covered, so an agent has everything needed to call this correctly.

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 description coverage is 100%, so the baseline is 3, but the description goes further by specifying the valid input combinations ('Pass linkedin_url, or first_name and last_name; company helps find the right person') — a fact the schema cannot convey since it marks zero parameters as required. That is genuine additive value.

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?

States a specific verb pair and resource ('Find and enrich professional profiles') and immediately enumerates the returned data, so an agent knows what it gets back. It explicitly contrasts itself with the 'emails' and 'companies' siblings, making disambiguation possible without opening any schema.

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?

Gives explicit when-to-use ('learn who a professional is and what they have done') plus two named alternatives with the condition that selects each ('For their work email use emails; for a company rather than a person use companies'). It also states the viable input combinations, which is the actual usage guidance for a 0-required-parameter tool.

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