get-file-data

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true. The description adds value by explaining the server-side fetch, return of a scaled image content block, and error behavior for non-rasterizable types. It does not contradict annotations and provides useful behavioral context beyond the 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?

The description is concise with three sentences that each serve a purpose: explain use case, describe output, and list limitations with alternative. There is no extraneous information. It is front-loaded with the core purpose.

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 has 4 parameters all well-documented in schema, annotations covering read-only and idempotency, and no output schema, the description adequately covers the main use case, error conditions, and sibling differentiation. It provides sufficient context for an AI agent to select and invoke the tool 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?

Schema description coverage is 100%, so the baseline is 3. The main description adds minimal parameter-specific context beyond what the schema already provides (e.g., mention of 'scaled rendition' relates to width). The schema descriptions for width and format are already comprehensive. Therefore, the description adds little extra semantic value.

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 tool fetches a wiki file server-side and returns the image inline as a content block for clients that cannot reach the wiki host. It explicitly distinguishes from the sibling tool 'get-file' by noting that for non-rasterizable types or metadata/download URL, one should use 'get-file'. This provides a specific verb and resource with clear scope.

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 explicitly specifies when to use this tool: for clients that are sandboxed or network-restricted and need the image for visual analysis. It also gives an exclusion: for other file types (audio, video, arbitrary binaries) and for metadata or download URL, use 'get-file'. This provides clear when-to and when-not-to guidance.

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