build_signed_url

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, but the description adds genuinely non-derivable behavior: it depends on the DREEP_SIGNING_SECRET server secret and the resulting URL is a bearer credential that anyone can use until expiry. That last point materially affects how an agent should handle the output. It stops short of saying what happens when the secret is missing or whether the signed URL embeds the transform.

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?

Three short sentences with zero filler: the operation first, then the precondition, then the security consequence. Nothing is repeated from the schema or annotations.

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 a full output schema, complete parameter coverage and annotations covering safety, the description only needs to supply the operational and security context, which it does. The remaining gap is the lack of explicit differentiation from build_delivery_url and create_upload_url among nine siblings.

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 per the rubric. The description adds no meaning about the four parameters, notably why both 'url' and 'asset_id' are required and which one actually gets signed, which is the main ambiguity an agent would face.

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 states a specific verb and resource: it builds a time-limited (signed) URL for an asset, and it scopes that to assets in a signed folder. That distinguishes it from the unsigned sibling build_delivery_url in substance, but the sibling is never named, so the agent must infer the contrast.

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?

Use is implied by the 'signed folder' qualifier and the warning about sharing, so an agent can infer this is for private assets. There is no explicit when-not guidance and no named alternative such as build_delivery_url for public assets, leaving the routing decision to inference.

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