tenki_get_upload_url

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

Annotations already signal readOnlyHint=false, idempotentHint=false, destructiveHint=false, and the description is consistent with them. It adds value beyond annotations by disclosing that the URL is short-lived (expires, so use promptly) and that the upload mechanism is HTTP PUT with a signed URL, which is effectively the auth model. It does not quantify the expiry or describe the response, but no contradiction exists and the added context exceeds the annotation baseline.

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?

Two sentences with no filler. The first sentence front-loads the core action and key traits (short-lived, signed, HTTP PUT, binary, sandbox path), and the second delivers the routing rule vs. tenki_write_file. Every clause earns its place.

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 3-parameter tool with a fully documented schema, safety annotations, and a clear sibling-routing rule, the description is nearly complete. Small gaps: the agent must infer that after obtaining the URL it must perform the PUT itself, the 'short-lived' duration is unquantified, and there is no output schema describing the returned URL structure. These are minor and do not block correct invocation.

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 100%: each parameter (path, session_id, content_type) already has descriptive text with examples and provenance hints (e.g., session_id 'from tenki_create_sandbox or tenki_list_sandboxes'). The tool description itself does not add parameter-level meaning, so the baseline 3 applies.

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 names a specific verb+resource: getting a short-lived signed URL for HTTP PUT upload of a binary file into a sandbox path. It also distinguishes itself from the closest sibling (tenki_write_file) by explicitly scoping itself to non-text/binary/large payloads, and the upload direction contrasts with tenki_get_download_url.

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 the selection condition: use when payloads are non-text, too large, or binary, instead of tenki_write_file. This names the alternative and the precise triggering criteria, leaving nothing for the agent to infer.

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