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

Annotations already flag this as a destructive, non-read-only, open-world write. The description adds substantial context beyond them: create also builds the first pipeline card, update preserves omitted fields and accepts null to clear, reassignment moves activities and the conversation while invoices keep their original client, closed deals lock value and service, and closing a deal closes its conversation ticket and can fire integrations. These side effects are exactly what an agent needs and are not derivable from annotations.

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?

Front-loaded with the action list, then prerequisites, then side effects, then sibling routing, then the delete boundary. Every sentence is functional, though the dense run-on enumeration of required fields and null-clearing rules makes it a heavy read with little visual structure.

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 13-parameter multi-action mutation tool with no output schema, the description covers required inputs, side effects, state locks, reassignment consequences, integration triggers, and sibling alternatives. Nothing an agent needs to invoke it correctly is missing.

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 92%, so the baseline is 3. The description goes further by stating cross-parameter constraints the per-field schema cannot express – create requires user_id/pipeline_id/stage_id/title plus either value or service_id, and the null-clearing/locking rules for company_id, owner_id, service_id, and value on update.

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 opening sentence names the exact resource (sales deals) and enumerates every action the tool supports (create, update, mark_won, mark_lost, reopen). It also explicitly distinguishes itself from pipeline-item-write, deal-activity-write, and deal-message-write, so an agent can route without opening the sibling schemas.

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?

Gives concrete when-to-use conditions for each action, including create prerequisites (user_id, pipeline_id, stage_id, title, and either value or service_id) and the boundary 'Does not delete deals.' It also names the alternatives and the conditions that select them (pipeline-item-write to move cards, deal-activity-write with deal_id, deal-message-write for client messages).

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