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

Annotations already indicate it is a write operation (readOnlyHint=false) and not destructive (destructiveHint=false). The description adds value by disclosing the return of 'the full updated/created object' and the active-space scoping with the space_id override. This goes beyond the annotations without contradicting them.

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 two sentences, front-loaded with the core purpose, then return value and scoping. Every sentence earns its place 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?

The tool has a complex body with nested objects and no output schema. The description covers scoping and return type but leaves ambiguity around the 'created' behavior for a tool named update_ad and defers nested object shapes to an external OpenAPI spec. This is adequate but not fully self-contained.

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?

The schema covers all three parameters with descriptions, and the description adds key semantics like 'partial update' meaning only provided fields are changed. The space_id parameter is well explained in the schema. Nested object fields defer to the OpenAPI spec, which is a minor weakness, but the overall parameters are reasonably clear.

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 'Partial update of an ad', which is a specific verb+resource combination that distinguishes it from create_ad and delete_ad. It also indicates the return behavior and space scoping, making the purpose unambiguous.

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 provides actionable guidance on space handling: it references set_active_space for switching and allows pass space_id for a one-call override. It does not explicitly mention alternatives like create_ad or delete_ad, but the 'partial update' phrasing implies this tool is for modifications, leaving a minor gap.

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