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

Annotations only mark it as non-read-only, open-world, and non-destructive. The description adds substantial behavioral detail: posts are public, images are hosted, previews return previewId and hosted URLs, changes after preview are refused, each preview publishes at most once, and confirmation must follow user approval. These are critical traits not captured by annotations.

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 dense but front-loaded: it opens with the purpose, then image constraints, then the two-step workflow and safety rule. Every sentence carries operational information; no runtime detail is wasted.

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 complex write tool with no output schema and no required parameters, the description explains the preview return shape (hosted URLs, previewId, posting identity) and the idempotent confirm behavior. It gives enough for an agent to call both steps correctly and avoid accidental publication.

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 coverage is already 100%, so the baseline is 3. The description still adds useful constraints beyond the schema: max 5 MB per image, approximately 3 MB total for inline images, and the requirement to reuse the preview's hosted image URLs exactly on confirm.

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?

Names a specific verb and resource ('Publish a PUBLIC post to the Swop feed') and scopes it to the linked account's SmartSite. It distinguishes the tool from siblings by contrasting its two-step preview/confirm flow with swop_send, so an agent can identify it as the feed-posting tool.

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?

Gives a clear workflow: call without confirm to get a preview, show the user, then confirm with the same caption, smartsiteId, images, previewId, and confirm: true. It references swop_send as a similar pattern but does not explicitly state when to choose this over swop_send or other posting tools, so it falls short of full alternative routing.

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