from_file

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It states that the tool describes a single file using Gemini, but provides no detail on what happens — whether it reads local files only (implied by 'path' but not stated), behavior of the 'compact' parameter, error handling, file size limits, or whether multiple files are rejected. There is no mention of the alias relationship's behavior implications. The description is too thin to convey meaningful behavioral transparency.

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 one sentence and extremely efficient: 'Alias for vision_from_file — describe a single file using Gemini.' There is zero waste. However, it is under-specified rather than concisely complete — brevity here trades off against missing critical guidance about when to use this vs alternatives. It earns a 4 for being tight, but this is brevity bordering on underspecification.

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?

The tool has 4 parameters (3 required), an output schema, and 14 highly-similar sibling tools. The description does not address the most important contextual question: how does this alias differ from its target vision_from_file, and when should an agent choose one over the other? The output schema exists so return values need not be explained, but the selection criteria among the dense sibling set is entirely absent. For a tool with this many near-identical siblings, the description is materially incomplete.

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 all 4 parameters (path, type, prompt, compact) are documented in the schema itself. Per the rubric, baseline is 3 when schema coverage is high. The description adds no parameter-specific information beyond what the schema already provides — the 'single file' nuance is the only marginal addition. No extra format, validation, or interaction guidance is given.

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 states it is an 'Alias for vision_from_file — describe a single file using Gemini.' This clearly identifies the verb (describe), resource (single file), and scope (using Gemini). However, it doesn't add meaningful purpose beyond what the tool name and sibling name suggest — it's essentially a pointer to another tool rather than a standalone description. It distinguishes from 'from_files' (plural) but mostly through the alias reference.

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 only says it's an alias for vision_from_file. It doesn't state when to use this tool vs the sibling vision_from_file or when to use from_file(s) vs the vision_* variants. No exclusions or contextual guidance are provided. The sheer number of closely-related sibling tools (from_files, from_resources, from_files_mixed, from_resources_mixed) makes the lack of differentiation particularly problematic — an agent could not distinguish correct usage from the description alone.

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