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

Discloses rich behavior beyond annotations: text types return as utf8 text while everything else returns whole/unparsed base64 with mimeType, a 1 MB size cap, and quota consumption on first read of assistant-produced files. This context explains why readOnlyHint=false despite the 'read' verb, so no contradiction.

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?

Front-loads purpose, then encoding behavior, then limits and the alternative in a logical order. Dense but each clause carries distinct, useful information; slightly packed but not wasteful.

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 still specifies the return format (utf8 text vs base64+mimeType), size limits, quota behavior, and the sibling alternative. Nothing an agent needs to call or interpret the result 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?

Schema coverage is 100% and both parameters (fileId, projectId) are already documented with their source list tools. The description adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb+resource ('Read an uploaded project file's contents') and explicitly contrasts with the sibling 'fastero_read_python_file' for Python projects. An agent can distinguish it from the other read/list tools 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?

Names the alternative tool (fastero_read_python_file) and the condition that routes to it (Python project files), and describes refusal conditions (over 1 MB, exhausted AI file downloads). The when-not guidance is explicit rather than inferred.

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