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

Annotations only indicate this is a mutating, non-destructive operation. The description adds meaningful behavioral context: lead_id is auto-set by Matrix on Qualified lead conversion, creating into a won stage immediately stamps the deal closed, and missing contact_id leaves the deal without a counterparty. This goes beyond what annotations provide.

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?

The description is front-loaded with the core definition, then efficiently explains each important parameter without redundancy. Every sentence adds value, from the counterparty requirement to the won-stage side effect, and the prose remains tight.

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 10-parameter create tool with no output schema, the description covers the essential domain logic, required relationship, and a caution about won-stage behavior. It does not mention the return value or every parameter, but enough context is provided for an agent to call the tool correctly in most situations.

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%, so the description carries meaningful weight. It clarifies the domain semantics of contact_id, lead_id, and status beyond their schema descriptions, explaining why they matter and how they interact. Some parameters like value and win_probability remain underexplained, but the most ambiguous ones are covered.

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 clearly states the action and resource: 'Create a CRM deal' with a definition of what a deal is (a named opportunity with value, stage, and close date). It also differentiates from related siblings by explaining that a deal is how a contact enters the pipeline and by referencing crm_get_deals for stage names.

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?

The description gives practical guidance on when to set lead_id, warns that a deal without contact_id has no counterparty, and tells the agent to ask before creating a deal directly into a won stage. It does not explicitly contrast with crm_update_deal, but the usage context is clear enough for correct invocation.

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