Upload File

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

Goes well beyond the annotations by disclosing non-obvious quirks: Content-Type is not persisted, mime_type is inferred from file extension, and contentBase64 is decoded leniently so garbage silently produces 0-byte uploads. It also adds a validation directive, which is exactly the kind of operational context an agent needs.

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?

Every sentence earns its place: purpose, verification step, large-file alternative, and two behavioral caveats. The structure front-loads the core action and then groups important caveats logically with no 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 5-parameter mutation tool with no output schema, the description covers verification, an alternative for large files, and validation pitfalls. It does not describe the response shape or auth requirements, but the explicit 'Verify with kaiten_list_files' mitigates the missing return-value information.

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 description adds extra value by warning about contentBase64 leniency and re-emphasizing that contentType is ignored. It does not add meaning for cardId, fileName, or verbosity, but those are self-explanatory.

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 action and resource: 'Upload file attachment (base64).' The description also differentiates it from file-related siblings like kaiten_list_files and kaiten_delete_file by implying this is the creation operation, with verification delegated to list_files.

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 explicit follow-up guidance: 'Verify with kaiten_list_files' and provides an alternative for large files: 'Prefer description links.' The alternative tool is not named explicitly, but the condition and workflow are clear enough for an agent to act on.

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