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

The destructiveHint=true annotation covers the safety profile, and the description adds genuine behavioral value beyond it: 'peopleIds/userIds replace the full list' discloses replace-not-append semantics, and 'PUT /v1/deals/{id}' signals full-representation update semantics. It does not mention auth requirements or what happens to omitted fields, but the replace disclosure is the critical non-obvious trait.

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, front-loaded with the core action, followed by the key behavioral caveat and the API mapping. Every clause earns its place, though the 'FUB: PUT /v1/deals/{id}' shorthand is somewhat cryptic as trailing metadata.

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 mutation with no output schema and destructiveHint set, the description covers the operation and replace semantics but omits auth requirements, treatment of unspecified fields, and any date-format or validation expectations. Adequate but leaves real gaps for a wide update surface.

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% on 14 params, so the schema does not carry the burden. The description groups parameters (stage, price, dates, people, agents) and clarifies replace semantics for peopleIds/userIds, but leaves the many date fields (possessionDate, dueDiligenceDate, earnestMoneyDueDate, finalWalkThroughDate, mutualAcceptanceDate), commissionValue, name, and description without any added meaning or format guidance.

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 categories: stage, price, dates, people, agents. The resource 'deal' clearly separates it from sibling mutators like fub_update_person and fub_update_task, though it never names those siblings 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?

There is no explicit guidance on when to use this versus fub_create_deal (new deal) or fub_update_person (record edits). Usage is only implied by the verb, and no prerequisites, exclusions, or alternative routing are given.

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