read_image

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

With no annotations, the description carries full burden. It discloses that the tool reads from the filesystem, returns base64 ImageContent, and supports specific formats. It does not mention error handling (e.g., file not found, unsupported format) or permissions, but for a simple read operation, the disclosure is fairly comprehensive.

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 two sentences, front-loaded with the core action. Every sentence adds value: the first explains what it does and output format, the second lists supported formats. No redundant or verbose language.

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 simplicity (one parameter, no output schema, no annotations, no siblings), the description is adequate. It covers purpose, input, output format, and supported types. It could mention that the operation is read-only and safe, but overall it is complete enough for an agent to use correctly.

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?

The input schema already describes the 'file_path' parameter as 'Absolute path to the image file'. The description does not add new meaning beyond this, so it meets the baseline of 3 for 100% schema coverage.

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 clearly states the verb 'Read', the resource 'image from the filesystem', and the output 'base64-encoded ImageContent'. It lists supported formats, making the purpose unambiguous. No sibling tools exist, so differentiation is not needed.

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 implies usage when needing to read an image as base64, but it does not provide explicit guidance on when to use this tool versus alternatives, or any prerequisites or exclusions. No siblings exist, so the lack of alternatives is not a penalty, but the description could still benefit from stating typical use cases.

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