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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description adds real value by naming the three checks performed (parser, step-key check, renderer) and stating it reports what is wrong. It stops short of describing the shape of the report or the cost of running the renderer.

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 tight sentences, with the core behavior and the no-side-effects guarantee front-loaded and zero 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?

With a nested-object parameter and no output schema, the description tells the agent it gets back a report of problems 'if anything', which is enough to act on. A brief note on the report's shape or the requirement for a version-1 document would have made 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 description coverage is 100% for the single required `doc` parameter, so the schema already carries the semantics. The description adds no detail about the document structure (version 1, nested objects) beyond what the schema states, so 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 (validate/run through parser, step-key check and renderer) and resource (an onboarding document), plus the key scope qualifier 'changes nothing'. The comparison to 'the same parser ... a save uses' implicitly separates it from save_onboarding_doc, and the 'onboarding' qualifier distinguishes it from validate_paywall_doc.

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?

'Changes nothing' and 'the same parser a save uses' make the pre-save validation context clear without naming save_onboarding_doc explicitly. There are no explicit exclusions or a direct pointer to the sibling it complements, which keeps it out of the top band.

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