validate_design

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: it returns 'totals plus paginated diagnostics' and warns that 'a plan-ready graph is not proof of rendered correctness', which tells the agent what validation does not guarantee.

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 scope, then the return shape, then an important caveat. No filler; the only blemish is the stray quotation marks around 'draft or complete mode'.

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 validation tool with no output schema, the description covers the action, scoping, mode semantics, and the shape of the return (totals plus paginated diagnostics). It is a bit thin on how diagnostics are grouped, but nothing critical for invocation is missing.

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 the schema already documents designId, pageId, cursor, revision, and the draft/complete enum. The description only echoes the mode and page scoping without adding format or interaction detail, 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 ('Validate a design session') plus scope options (a single page, draft/complete modes), so the agent knows exactly what is being validated. It does not, however, distinguish itself from the close siblings validate_composition and validate_markup, which an agent would need help telling apart.

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 mention of 'draft or complete mode' implies when each strictness level applies. But there is no explicit guidance on when to call validate_design versus validate_composition or validate_markup, nor any stated prerequisites (e.g. an existing session), so usage must be inferred.

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