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

Annotations already declare non-destructive, open-world, non-idempotent write behavior, so the description adds real value on top: 'the vendor says what is missing' discloses server-side validation error behavior, and 'Nothing is sent to the contact' rules out an email/notification side effect the agent might otherwise worry about. Success return shape is 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 WRITE marker and operation, then prerequisite lookup, then conditional requirements, then the side-effect caveat. Nothing is filler.

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 an 11-parameter write tool with no output schema, the description covers lookup prerequisites, conditional requirements, validation behavior, and side effects. It omits any statement about what a successful call returns (e.g., the created deal id), which an agent would want with no output schema available.

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 100% so the baseline is 3, but the description adds a cross-parameter dependency the schema cannot express: pipelines with a monetary value or target date require value and target_date. The value_type default note merely restates the schema.

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?

Opens with a specific verb and resource ('WRITE: create a deal (sales opportunity)') plus the endpoint POST /deals, which cleanly separates it from get_deal, update_deal, and list_deals in the sibling set. An agent can identify the operation 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?

Explicitly routes the agent to list_deal_types for pipeline and stage ids, and states a conditional prerequisite (value and target_date required when the pipeline has a monetary value or target date). No explicit when-not-to-use guidance against update_deal, which keeps it from a 5.

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