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

Annotations declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, covering the safety profile. The description adds valuable context beyond that: the upload_id comes from swiftly_request_upload, and importantly that this tool is UI-called rather than model-called. This sourcing dependency is behaviorally meaningful.

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 tight sentences, front-loaded with the core purpose, then caller constraint, then the alternative. No redundancy.

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 2-param tool with full schema coverage and no output schema, this covers purpose, caller, provenance of upload_id, and the sibling alternative. The one missing element is what happens on failure or what the return looks like, though no output schema exists to cover return structure.

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%, with clear descriptions for upload_id ('upload ID returned by swiftly_request_upload') and files. The description adds the provenance of upload_id, which the schema already states. Baseline 3 per high 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?

States a specific verb and resource: 'Process files from the upload panel and add them to WordPress media library.' Distinguishes it from wp_upload_media by naming that sibling as the URL-based alternative.

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?

Explicitly states who calls it ('Called by the upload UI (not by the model)') and names the alternative (wp_upload_media for URL-based uploads). This is unusually clear routing guidance, even telling the agent it should not invoke this tool.

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