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

Beyond the annotations (readOnlyHint=false, destructiveHint=false) the description discloses real behavior: colors must be #RRGGBB, too-light colors are rejected with a suggested alternative, logo must be https png/svg/webp under 512 KB, and the logo_url field doubles as a removal mechanism via empty string. The Free/Pro entitlement gating is behavioral information an agent could not get from the schema or annotations.

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 prerequisite is front-loaded in parentheses and every subsequent sentence carries a distinct constraint (validation, entitlement, format). The style is telegraphic and dense — the Free/Pro list reads as shorthand rather than prose — but no sentence is 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 7-parameter mutation with no output schema, the description covers prerequisites, validation rules, and entitlement limits, which is most of what an agent needs. It omits partial-update semantics and whether the call returns the resulting branding, leaving a small but real gap for a write operation.

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 the baseline is 3, but the description adds value the schema does not carry: it partitions the parameters into Free (display name, colors, tagline) and Pro (logo_url, login_message), which changes what an agent should attempt to set. It does not address whether omitted fields are left untouched or cleared, which is the remaining semantic gap.

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?

"Change how the back office looks" plus an explicit field inventory (display name, colors, tagline, logo_url, login_message) makes the resource and effect clear. It never names get_branding or reset_branding, so the agent must infer that this is the write counterpart, but the purpose itself is 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?

It states the prerequisite ("Needs the workspace_key from create_workspace") and a workflow rule ("Confirm colors with the owner in plain words first"), plus a Free vs Pro split that tells the agent which fields are even available. It stops short of naming an alternative such as get_branding for reading or reset_branding for reverting, so there is no explicit when-not guidance.

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