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

Even with annotations covering readOnly and safe behavior, the description adds crucial behavioral context: it warns that content is returned boxed as UNTRUSTED CODE and must be treated as inert source, and it explains that updatedAt should be passed as expected_updated_at when proposing edits. This goes well beyond the annotations and helps the agent handle output responsibly.

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 mostly concise and front-loaded with the core purpose. The final 'Routing' sentence is somewhat redundant, but the rest earns its place with the untrusted-code warning and usage guidance.

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 no output schema, the description explicitly mentions the returned content is raw source code and that updatedAt is included, and explains how to use updatedAt. This is sufficient for the simple read-only tool, though it does not detail the exact return shape or error behavior.

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 each parameter. The description adds a filename example (sections/header.liquid) but does not meaningfully enrich theme_id or companyId semantics. 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 tool gets one Shopify theme file's raw source code by theme id and filename, with examples. It adds the specific use case ('Use before proposing an edit') and a routing line, making the purpose unambiguous and distinct from siblings like list_shopify_files or list_shopify_themes.

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 explicitly says to use it before proposing an edit to a theme file to see current code, giving clear when-to-use context. It does not, however, name alternative tools or state when not to use it, so it falls short of fully explicit usage exclusions.

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