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

Annotations already indicate this is a write operation (readOnlyHint=false). The description adds nothing beyond the basic edit verb; it does not disclose whether updates are partial (only provided fields) or full replacement, nor any side effects or idempotency behavior. With minimal annotations, the description should carry more burden but does not.

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 a single sentence with no waste, front-loading the action and resource. It lists the editable fields concisely. Slightly listy but acceptable for clarity.

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 8-parameter mutation tool with an output schema, the description is minimal. It does not clarify partial vs full update semantics, does not mention any constraints or validation, and omits the need to first fetch screen_id via list_product_screens (though schema mentions it). An agent would need to infer behavior from the schema alone, which is not ideal.

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 all parameters have descriptions. The tool description adds only a loose grouping of 'screenshot tags' (screen_type, device, theme), which is marginal value. It does not explain the relationship between screen_id and list_product_screens, which is already in the schema. Baseline 3 is appropriate.

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 verb 'Edit' and the resource 'existing brand asset', listing the specific fields to be modified. This distinguishes it from siblings like upload_product_screen (create) and delete_product_screen (destroy), and from update_brand_dna (different asset type).

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 no explicit guidance on when to use this tool versus alternatives. It does not mention that screen_id must be obtained from list_product_screens, nor does it state any exclusions or conditions. The usage context is only implied by the verb 'Edit'.

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