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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description still adds meaningful context beyond them: eligibility preconditions, an explicit statement of what it does not create, and a threshold behavior ('More than 20 candidates requires manual review; never select silently'). What 'manual review' entails operationally and how results are ordered or capped remain unstated.

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?

Four short sentences, front-loaded with the core read operation, then preconditions, then next step, then guardrail. Every sentence carries information, though the compressed jargon ('business facts', 'native phone decision flow') costs some immediate clarity.

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 read-only tool with no output schema, the description covers eligibility, preconditions, downstream usage, and a safety guardrail. It leaves the shape of returned candidates (beyond the implied offerId) and the no-results case unspecified, which is a minor gap rather than a blocker.

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 0%, so the description must carry the meaning of reservationId. It partially does by saying the read is 'for one tenant reservation', implying the parameter identifies that reservation, but it gives no format, source, or validation hints. The single parameter is at least semantically inferable, which keeps it at minimum viable rather than lower.

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 uses a specific verb and resource ('Read existing pending supplier offers eligible for the native phone decision flow') and scopes it to 'one tenant reservation'. It also fences the tool off from adjacent operations with 'No new offer, price, call or assignment', so an agent can tell it apart from prepare_supplier_call without opening the 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?

It states a prerequisite ('Requires confirmed paid, unassigned business facts') and an explicit next step ('Copy an existing offerId to prepare_supplier_call'), which is real routing guidance. It does not explicitly say when to prefer this over get_supplier_call or what to do if no candidates exist, so it stops short of full when/when-not coverage.

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