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

Annotations only establish that this is a non-destructive write operation. The description adds the real behavioral context: presigned upload_url and logo_key are returned, a single HTTP PUT with no extra headers is required, the url expires (expires_in_seconds), the image is capped at 2 MB, and the size is re-checked later at set_agent_logo.

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-loaded with the purpose, then the required arguments, the return contract, and a concrete curl example. Every part is useful, though the sequence runs a few sentences long and the inline example could be trimmed without loss.

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?

No output schema exists, so the description compensates by naming the return values (upload_url, logo_key, expires_in_seconds) and describing the full upload-then-attach lifecycle. For a multi-step presigned-upload tool, nothing needed to invoke it correctly is missing.

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%, so the baseline is 3, but the description adds meaning beyond the schema: it identifies the agent id as a hashid from list_agents, enumerates the allowed content_type values in prose, and clarifies the optional size param is rejected up front. Only the size/filename handling overlaps with the schema.

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 and resource ('Start uploading a logo image for one of the team's agents') and immediately scopes it to the watermark feature tied to composition_parameters.logo_watermark_enabled. Clearly distinguishes this from set_agent_logo, which is named as the follow-up step.

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 an explicit end-to-end flow: call this tool, PUT the raw bytes, then call set_agent_logo with the same agent and logo_key. It also names list_agents as the source of the agent hashid, so the agent knows exactly when and how to use this versus the sibling.

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