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

Beyond the annotations, the description discloses the actual mechanics (bytes go to an API-issued private S3 URL, then the document is attached in Tripsy), that no Tripsy credentials reach S3, the Pro entitlement requirement for owners, and that server-side membership/permission checks apply. It also flags file contents and metadata as untrusted data, which is real behavioral guidance. Slight deduction because the closing 'Safety: Open-world...' sentence largely restates the openWorldHint annotation and the S3 URL behavior already described above.

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 most important constraints — size limit and the sibling alternative — are front-loaded in the first two sentences, which is good structure. However, the safety sentence repeats the S3 upload flow and open-world fact already stated earlier, and could be trimmed without losing 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 mutation tool with an output schema present, the description covers the essentials: size limits, the correct sibling workflow, permitted input forms, entitlement rules, server-side permission enforcement, and credential handling. Nothing critical for a correct call is missing, though the entitlement/permission sentences sit slightly at odds with the schema's parent_id/parent_type complexity, which is left to the schema alone.

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 all eight parameters, including the 8 MiB decoded limit and the no-paths rule for content_base64. The description's parameter-related content (size cap, no paths/URLs) duplicates the schema rather than adding new semantics. Baseline 3 is the right score when the schema does the heavy lifting.

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 first sentence names a specific verb and resource ('Upload and attach standard base64 document bytes') plus a hard size bound, and the second sentence names the sibling alternatives (upload_prepare then attach) for the out-of-scope case. An agent can distinguish this from tripsy_documents_attach and tripsy_documents_upload_prepare without opening any 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?

It gives an explicit routing rule: files up to 8 MiB use this tool, larger files must use upload_prepare followed by attach. It also states clear exclusions ('No file paths or arbitrary upload URLs are accepted'), so the agent knows what not to attempt.

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