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

Annotations already declare readOnly/non-destructive/closed-world, so the description adds real value beyond them: it discloses that the response carries the current revision and that an empty path switches the behavior to a file listing with sizes. It doesn't describe error behavior for invalid paths, but that is a minor omission against solid annotation coverage.

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?

Three sentences, front-loaded with the core action, then the empty-path behavior, then the path grammar. Every clause carries information an agent needs to form a valid call.

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 two-parameter read tool with no output schema, the description covers both parameters' semantics and the response's revision-bearing nature. Remaining gaps (failure modes, revision format) are small relative to the tool's simplicity.

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 coverage is 50% – slug is documented in the schema, path is not. The description compensates by enumerating valid path forms (theme.json, sections/<name>.json, templates/<handle>.json, etc.) and explaining the special empty-path case, adding meaning the schema lacks.

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?

Specific verb+resource ('Read one file of an own theme') with scope clarified as 'with its current revision'. An agent can distinguish this from write_own_theme_files or check_own_theme without opening a schema.

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 implicitly tells you how to discover files (empty path lists every file with size), which is genuinely useful usage context, but never names an alternative tool or states when not to use this one versus write_own_theme_files or screenshot_own_theme.

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