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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered; the description usefully adds the brand-kit dependency and enumerates the rule categories being evaluated. However, with no output schema it never says what a result looks like — pass/fail, per-line issues, severity — which matters for a checker whose whole value is its findings.

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?

Two sentences, verb front-loaded, with the rule categories compressed into a single colon list and the prerequisite stated last with no padding. Nothing could be cut without losing information.

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 read-only 3-parameter validator the description covers purpose and preconditions well, but with no output schema the omission of any return-value description leaves an agent unable to anticipate the response shape. Adding one clause on what the check reports would make it complete.

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 67%, so the baseline is 3. The description hints that 'text' holds the lines of copy and that graphics have a length constraint tied to kind=graphic, but it never mentions the kind enum values (graphic/text/caption) or the projectId default, adding little beyond the schema.

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?

Specific verb+object+scope: 'check lines of on-screen copy against the project brand's voice', followed by a concrete checklist (avoided words, emoji, exclamation marks, case, length, template phrases). It is clear this is a validation tool rather than an editor, though it never names a near-sibling like check_edit to sharpen the boundary.

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?

'before using them' states the point in the workflow at which to call it, and 'Nothing to check without a brand kit' is an explicit precondition/exclusion. It stops short of naming what to do instead when no brand exists (e.g. import_brand, set_project_brand, list_brands).

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