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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds real context beyond that: the shape of the returned record and the fact that related records are excluded unless explicitly requested via expand, which materially changes the result set.

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 tight sentences plus the endpoint path, with the core purpose and the expand mechanism front-loaded. Every sentence earns its place; the raw path is mildly redundant but useful for API mapping.

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 does the work of sketching the return payload and the optional expansions, which is sufficient for an agent to call it correctly. Rate limits or error behavior are unmentioned, but that is a minor gap for a simple read.

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 50% — document_id is documented, but expand has only a type/pattern and no enum or explanation. The description compensates by enumerating the seven accepted expand values, which is the single most important piece of missing information.

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 and resource — fetch a single document by id — and enumerates the payload contents (amounts, dates, state, links). The singular "one document by id" implicitly separates it from bsale_list_documents, but no sibling is named explicitly.

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 tells the agent to use expand for line items, payments and related records, which is actionable guidance for a common follow-up need. However, it never states when to prefer this over bsale_list_documents or which sibling to use when the id is unknown, leaving selection largely implied.

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