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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds useful context beyond annotations by specifying it 'parses JSON only' and does not perform semantic validation, which informs the agent of the tool's limited scope and prevents misuse.

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 description is extremely concise, consisting of two sentences that deliver all necessary information upfront. Every word earns its place, with no filler or redundancy.

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?

Given the presence of an output schema, rich annotations (read-only, idempotent, non-destructive), and a single well-documented parameter, the description fully covers the tool's behavior and limitations. It is complete for the tool's simplicity and the structured data surrounding it.

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?

The input schema already covers the single parameter with a clear description ('Raw HTML markup supplied by the user; this is not a webpage URL.'). The tool description reinforces 'supplied HTML' but adds no additional parameter meaning, so 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?

The description clearly states a specific action: 'focused JSON-LD syntax check of supplied HTML'. It distinguishes itself from other validation tools by explicitly noting it does not validate Schema.org vocabulary semantics, which sets it apart from broader audit tools.

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 description opens with 'Use this for a focused JSON-LD syntax check', providing explicit when-to-use context. It also gives a clear exclusion: 'does not validate Schema.org vocabulary semantics', which tells the agent when NOT to use it, though it does not mention alternative tools by name.

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