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

Goes well beyond the annotations: it discloses that the call may trigger the site's complaint workflow and notifications, spells out the concrete consequence of non-idempotency (two complaints), and explains that server-side validation rejects requests missing required fields. This is exactly the side-effect context the destructiveHint=false / idempotentHint=false flags cannot convey.

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 operation mode and the highest-risk behavior (side effects, non-idempotency) before validation notes and the endpoint path. Three tight sentences plus endpoint, with no 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 a 13-parameter write with a nested contact object and no output schema, it covers the critical gaps: side effects, idempotency, and where identifier values come from. It is slightly thin on the vague 'rejects a request that lacks required ones' phrasing (schema lists only description as required) and on the contact_person sub-fields.

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 field-level meaning is already handled; the description nevertheless adds the useful fact that ids like source, company and recorded_by are GUIDs drawn from the site's own lists, which is not obvious from the pattern constraint alone. It says nothing extra about the nested contact_person object or the date/risk formats.

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 an explicit 'WRITE: record a NEW complaint' verb+resource+mode, which cleanly separates it from all read-oriented siblings (get_complaint, list_complaints) and from the update tools. An agent can pick it without opening any 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?

The 'WRITE:' marker plus the explicit 'not idempotent: calling it twice creates two complaints' tells the agent when to be cautious about repeating the call. It stops short of naming an alternative tool or stating prerequisites (e.g., fetch site lists first), so it is clear context without full routing guidance.

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