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

Annotations already indicate readOnly, idempotent, and non-destructive behavior. The description adds genuinely useful behavioral traits: 'Deterministic, evidence-bounded and signed,' plus the exact cost and a statement about not hiding upstream cost. No annotation contradiction exists.

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 compact and front-loads the core action and resource. The punctuation is slightly awkward ('without hiding upstream cost.; 0.120 USDC.'), but overall every fragment contributes meaningful information.

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 description is adequate for a simple read-only, idempotent enrichment call, and an output schema exists. However, given the large sibling tool list and an open input schema, the description does not fully clarify how to structure the request or how this tool relates to the enrichment evidence tools.

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?

With 0 formally defined parameters and an open-envelope schema, the baseline is 4. The description provides target-type semantics ('company, person or contact'), which is helpful, though it still does not specify what fields or identifiers a caller should supply.

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 names a specific action ('Enrich') on a specific resource type ('a company, person or contact') and adds the 'attributed provider route' qualifier. However, 'enrich' is not formally defined, and the description does not explicitly distinguish phion_enrich from phion_search, phion_inference, or the separate enrichment evidence siblings.

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?

No guidance is given for when to use this tool versus sibling tools such as phion_search, phion_inference, company_enrichment_evidence, person_enrichment_evidence, or contact_enrichment_evidence. There are no when-to-use, when-not-to-use, or alternative conditions.

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