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

With no annotations, the description carries the burden of behavioral disclosure. It usefully discloses that a missing profile returns 'nothing' and that this is not a billing problem, but it does not explain behavior when both or neither identifiers are supplied, or describe the return format.

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 focused sentences, no filler. The primary lookup behavior is front-loaded, and the second sentence adds meaningful context about the no-profile case without redundancy.

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 simple getter, the description covers the main purpose and an important edge case. It is incomplete regarding identifier selection rules and does not clarify what 'nothing' means in practice, especially since both parameters are optional and there is no output schema.

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 has 0% description coverage, so the description must compensate. It conveys that the profile belongs to one contact or company, which hints at companyId/contactId usage, but it does not explicitly map these to parameters or clarify whether one identifier is required given that both are optional in 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 clearly states the tool retrieves the billing profile for one contact or company and returns nothing when none exists. The verb and resource are specific, though it does not distinguish itself from the similarly named sibling billing_profile_get.

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 this is a single-profile lookup by contact or company, and explains the no-profile case. However, it gives no explicit guidance about when to prefer this over billing_profiles_list or billing_profile_get, nor does it state exclusions.

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