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

The description reinforces the readOnlyHint and idempotentHint by stating it's a 'read-only presentation tool' and 'creates no cart, checkout, order, or payment.' It adds a specific behavioral warning about not converting image or Markdown fallback to raw HTML, which is beyond the 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 description is a single, well-structured paragraph that front-loads the primary purpose and then adds conditions and warnings. Each sentence adds value (e.g., the negative usage case), and there is no redundancy or fluff.

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 that an output schema exists and this is a presentation tool, the description adequately covers the calling context: when to call, what to pass, and what it produces (a rendered card). It also warns about duplication and read-only nature, making it complete for an agent to safely invoke.

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 description mentions all five parameters by name ('same category, product handle, exact SKU, requested media types, and limit') and implies they must match the retrieval call, but provides little additional semantic detail beyond the schema's enums and defaults. It does clarify 'exact SKU' meaning consistency, but this is minimal.

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 verb ('render') and resource ('final HALO product-media card'), and distinguishes it from retrieval (get_homebridge_product_media) and configuration (configure_homebridge_fire_pit). It even names the sibling tool it is not.

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 provides explicit conditions for use ('only when the buyer explicitly requested additional images... and get_homebridge_product_media was just called') and explicit when-not-to-use ('NEVER call this after configure_homebridge_fire_pit merely to display the resolved product...'). It also points to the alternative tool and the reason (duplicate card).

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