prepare_image

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

With no annotations, the description carries the behavioral burden. It discloses key behavior: it returns a short ID, not a base64 payload, to avoid display slowdowns. It does not detail file-system side effects or error behavior, but the disclosed return behavior is concrete and useful.

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?

Three sentences, all front-loaded with the most important information: recommendation, what it does, and the key behavioral benefit. The alternative tool is named early, and no sentence is wasted on filler.

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 simple two-parameter tool with no output schema, the description covers the essential facts: what it takes, what it returns, and when to use it. It does not enumerate accepted image formats or define what 'prepare' entails beyond the ID return, but the core calling context is clear.

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%, so the schema already documents file_path and max_size_kb clearly. The description adds little parameter meaning beyond the schema, though it does imply max_size_kb's purpose via the point about avoiding display slowdowns. 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?

The description uses a clear verb ('prepare') and resource ('a local image file'), and states its purpose: returning a short ID instead of the full base64 string for use with other tools. It also explicitly distinguishes itself from read_local_image, making sibling differentiation immediate.

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 gives a direct recommendation ('Always use this instead of read_local_image') and specifies the applicable context ('for image transformation tasks'). This tells an agent exactly when to choose this tool over a closely related sibling.

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