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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds value by specifying the exact data returned (description, price, sale price, colors with SKU and stock), which is behavioral context beyond what annotations provide. It does not cover error handling or not-found behavior, but for a simple read-only get this is sufficient.

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 sentence that front-loads the core purpose ('One product by its slug') and then lists the return fields efficiently. Every word contributes; 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?

For a tool with only one well-documented parameter, annotations covering safety, and a description that lists the return fields, everything an agent needs to call it correctly is present. The absence of an output schema is mitigated by the explicit list of returned data. No critical information 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?

The schema has 100% coverage for the single 'slug' parameter with an example, so the description does not need to add parameter details. The phrase 'from search results' adds a hint about where the slug originates, which is a slight extra context, but the heavy lifting is done by the schema. Thus a baseline 3 is appropriate.

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 the verb 'Get' and the resource 'product', and specifies it retrieves a single product by slug. It distinguishes itself from siblings like search_products (which likely lists/search) and fetch (generic) by detailing the exact fields returned (description, price, sale price, colors with SKU and stock).

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 phrase 'from search results' implies the intended usage context—after obtaining a slug via search—but does not explicitly state when not to use this tool or name alternatives. It gives clear context for when to use it but stops short of explicit exclusions or comparisons to siblings like fetch.

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