attach_image

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

No annotations are provided, so the description carries the full burden, and it does substantial work: it discloses a client capability prerequisite, a directory restriction, and non-obvious format behavior (SVG returned as XML markup, BMP unsupported). It omits what a successful attachment returns or how failures surface, but the disclosed constraints are the ones an agent is most likely to trip over.

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-loaded with purpose, then capability context, then format constraints and caveats in a logical order. Slightly dense with parenthetical asides ('the formats vision models accept', 'convert to PNG'), but every sentence carries usable 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?

For a single-parameter tool with no output schema and no annotations, the description covers the vision-capability requirement, allowed-directory scoping, and accepted/rejected formats - the main things an agent needs to invoke it correctly. It could say more about what happens on success or unsupported input, but coverage is strong overall.

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% and the single 'path' parameter is already documented, including the guidance to pass an array even for a single image. The description's 'single image or multiple images at once' and format notes add modest meaning but do not go beyond what the schema already conveys. Baseline 3 is appropriate.

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 ('Attach') and resource ('image file') and immediately qualifies the outcome ('for AI vision analysis'), which cleanly separates it from text-oriented siblings like read_file or read_multiple_files. An agent can tell what this does without opening the 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?

Provides a clear use context ('enabling the AI to see and describe visual content, read text in images, analyze diagrams') and a prerequisite ('requires the MCP client to support vision capabilities'). It does not, however, name a sibling alternative or state when-not to use this (e.g., pointing text files to read_file).

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