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

Annotations already declare the safety profile (not read-only, idempotent, non-destructive, not open-world). The description adds genuine behavioral context beyond that: the logo surfaces in the dashboard brand list and on future posts' images, and the call succeeds even when no brand guide exists. It doesn't state replacement/overwrite semantics for an existing logo, but the added effect disclosure is substantive.

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?

Three short sentences, front-loaded with the action and its input constraint, with no redundant or filler text. Every sentence contributes a distinct fact (source, prerequisite, downstream visibility, edge-case allowance).

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 two-parameter mutation with full schema coverage and annotations carrying the safety profile, the description covers prerequisite, effect, and a notable edge case (no brand guide). No output schema exists, but the description conveys the observable outcome; only explicit overwrite behavior is left unstated.

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 description coverage is 100%, so both brandId and mediaLibraryAssetId are already documented with their sources (list_brands, upload_brand_image). The description reinforces the assetId provenance but adds no format, constraint, or edge-case detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource ('Sets a brand's logo'), names the source constraint (an existing image library asset), and distinguishes itself from the sibling upload_brand_image by clarifying the ordering relationship. An agent can tell exactly what this does versus the upload tool.

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 tells the agent to call upload_brand_image first and pass its assetId here, which is the key usage sequence. It also notes the operation works without an existing brand guide, removing a potential blocking assumption. It doesn't discuss alternatives for other logo-related workflows, but the routing guidance is clear.

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