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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read. The description adds useful behavioral context by requiring the buyer key and scoping the operation to registered agencies. It also enumerates the returned fields, which is the main expected behavior of a status endpoint.

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: the first lists the payload, the second gives the required credential. Every clause earns its place and the key requirement is front-loaded near the field list.

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 one-parameter tool with no output schema, the description carries the burden of explaining what the agent receives, and it does so with an explicit field list. It does not cover error behavior, empty states, or exact value formats, but those are minor for a simple status read with strong annotations.

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 sole parameter buyer_key is fully documented in the schema as 'Issued to the licensed contact at confirmation,' and the description restates this same detail. Since schema coverage is 100% and the description adds no new format, source, or validation information, it meets the baseline but does not exceed it.

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 identifies a clear resource (a registered agency) and enumerates the specific data it returns: states, rail, terms, founding period, queued/delivered counts, credit balance, and verification status. The title 'Agency status (buyers)' plus the buyer_key requirement helps separate it from registration or eligibility siblings. It lacks an explicit imperative verb like 'get' or 'retrieve,' but the intent is unambiguous.

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?

It states a clear precondition: the agency must be registered and the caller must hold the buyer key issued at confirmation. This implies it is used after registration rather than during eligibility checks or initial registration. It does not name alternatives such as status_dashboard, so exclusion guidance is absent.

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