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

Annotations only declare the generic safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), leaving the mechanics unexplained. The description adds genuinely non-obvious behavior: the URL is short-lived, the transfer is a raw HTTP PUT with Content-Type: text/html, a shell and unrestricted outbound HTTP are prerequisites, and a second call (finalize_upload) is mandatory to complete the operation. No contradiction with the 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?

Front-loads the what and the why in the first clause, then the how, then the failure mode and alternative. Every sentence carries information the agent needs; none is 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?

With no output schema, the description correctly supplies the return value (upload_path) and the exact follow-up call signature. It also covers environment prerequisites and the fallback tool, so an agent has everything needed to either execute or route around this tool.

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?

There is a single parameter and schema description coverage is 100%, so the schema already documents the account field, its default, and the list_accounts pointer. The description adds nothing about the parameter, which is acceptable given the schema does the work, but it is the minimum-viable baseline rather than added value.

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+resource ('Returns a short-lived signed upload URL') and immediately frames itself as 'Step 1 of 2' in a named workflow, so the agent knows exactly what it produces and what consumes it. It also names the sibling tools it pairs with (finalize_upload) and the one it competes with (host_html_content).

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 condition that selects it ('large HTML file that is already on disk, without sending its bytes through the model's context') and the condition that rules it out ('the PUT will not succeed where outbound network access is restricted'), naming host_html_content as the inline alternative. This is a textbook when/when-not/alternative block.

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