Read Media File

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds meaningful behavioral detail: base64 encoding, MIME type inclusion, content-type routing for image/audio versus other files, and the allowed-directories restriction. It does not describe error cases or file-size limits, but the core behavior is transparent.

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 three concise sentences with no filler. The primary behavior is front-loaded, followed by key type-routing details and a scope constraint. Every sentence contributes useful information.

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?

Given the tool's low complexity, a single parameter, rich annotations, and an output schema, the description covers the essential invocation requirements: what the tool returns, how different file types are represented, and the directory constraint. The main gap is the absence of explicit routing to sibling read tools, but the core invocation details are sufficient.

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?

There is only one parameter, path, and schema description coverage is 0%, so the description must compensate. It clarifies that the path must be within allowed directories, but it does not explain path format, absolute versus relative paths, or how to discover the allowed directories via list_allowed_directories.

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 a specific verb and resource: read a file and return it as a base64-encoded content block with its MIME type. It also differentiates behavior by file type (image/audio vs embedded resource), which makes the tool's function clear. However, it does not explicitly contrast it with the similar sibling tools read_file and read_text_file.

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 provides no when-to-use versus alternative guidance. It does not say to prefer read_text_file for plain text, read_multiple_files for batch reads, or how to decide between read_file and read_media_file. The 'only works within allowed directories' clause is a constraint, not usage guidance.

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