read_media_fileRead image or audio files within allowed directories, returning base64-encoded data and MIME type; files over 5,242,880 bytes are rejected.
Read an image or audio file. Returns the base64 encoded data and MIME type. Files larger than 5,242,880 bytes are refused with an error. Only works within allowed directories.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the safety profile is covered. The description goes beyond that by disclosing a precise failure threshold (files over 5,242,880 bytes are refused with an error), the returned encoding format, and the directory-scope limitation — three behavioral facts not present in structured fields.
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?
Four short sentences with the core purpose front-loaded, then return value, then hard limits, then scope. Every sentence carries distinct information and none is redundant with the schema or annotations.
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 correctly fills the gap by describing the return payload (base64 + MIME type) and the failure mode, plus the directory constraint. It is nearly complete for a one-parameter read tool; only path-format semantics are unaddressed.
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 0% for the single `path` parameter, so the description carries the burden but only partially compensates: 'Only works within allowed directories' hints at path resolution scope, yet nothing explains absolute vs relative paths, extensions, or how unsupported file types are handled.
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 and resource ('Read an image or audio file') and immediately says what it returns (base64 data plus MIME type). The media-versus-text distinction lets an agent infer its place among read_file/read_text_file, but it never names a sibling explicitly, so differentiation is implicit rather than stated.
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?
Usage is implied by the resource type and by two preconditions: a 5,242,880-byte size ceiling and the allowed-directories restriction. There is no explicit 'when to use this instead of read_text_file' routing guidance, so the agent must infer that non-media files belong to the other readers.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.