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

Annotations already declare idempotent=true, destructive=false, readOnly=false; the description adds genuinely new behavior beyond that: it is a partial/patch update ('Only the fields you pass are changed'), returns the full config, and has an external propagation side effect to connected SDK clients as bridge.app.branding. That downstream visibility is not captured by any annotation.

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 purpose and field-scoping rule, then the propagation effect, then the cross-tool pointer. Dense and mostly waste-free, though the final get_integration_guide sentence is somewhat tangential to invoking this tool.

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 partial-update tool with no output schema, the description supplies the mutation semantics, the return shape ('full updated branding configuration'), and the side effects. An agent has enough to call it correctly and anticipate consequences.

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 every parameter is already documented in the schema. The description names the same field set and adds brief CSS-format examples ("#1a1a2e", "8px"), which mostly duplicates the schema's own examples; the baseline of 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 (update) and resource (Bridge-hosted auth pages' branding) plus the exact scope of fields that can be set. It is clearly distinguishable from get_branding, the read counterpart in the sibling list.

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?

Gives clear context for the operation and a conditional route to a different tool ('before writing app code that renders a workspace logo, name or colours, call get_integration_guide with topic=branding'). It does not state when NOT to use this tool or when to prefer get_branding, so it stops short of full alternative coverage.

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