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

Annotations supply only destructiveHint=true, so the description carries most of the disclosure burden and it does add one genuinely non-obvious, high-value fact: peopleIds/userIds replace the full list rather than append. It does not resolve the larger question for a destructive 14-parameter update — whether omitted fields (name, price, dates, description) are left untouched or cleared, nor any permission requirements.

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 an API mapping note, with the core capability and the destructive list-replacement warning front-loaded. No filler sentences and nothing repeated from the title.

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 14-parameter destructive mutation with 21% schema coverage and no output schema, the description gives the essential scope and one critical caveat but leaves the partial-vs-full update semantics and date string formats unaddressed. It is usable but incomplete for an agent to call with confidence.

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 only 21%, so the description must compensate; it partially does by grouping the parameters into categories (stage, price, dates, people, agents) and by explaining the replacement behavior of the two array parameters. However, the seven-plus date and value fields (commissionValue, possessionDate, dueDiligenceDate, projectedCloseDate, earnestMoneyDueDate, finalWalkThroughDate, mutualAcceptanceDate) get no format or meaning added anywhere.

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 ('Update a deal') and enumerates the mutable dimensions — stage, price, dates, people, agents — so an agent knows exactly what the call can change. It does not explicitly contrast itself with fub_create_deal or fub_update_person, so sibling differentiation is left implicit.

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?

There is no when-to-use guidance, no mention of when not to use it, and no pointer to alternatives such as fub_create_deal for new deals or fub_update_person for contact changes. The only usage-adjacent statement is the replace-list semantics for peopleIds/userIds, which is behavioral rather than routing guidance.

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