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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered structurally. The description adds genuinely non-obvious behavioral context beyond that: the relative cost ('a fifth as much') and the shape of the result ('one asset instead of the whole record'). It does not discuss caching, auth, or rate limits, keeping it short of a 5.

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 output form is front-loaded in the appositive, and the routing rule against 'brand' follows immediately, so 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?

With no output schema, the description usefully characterizes the return value as a single embeddable image URL, which is the key thing an agent needs. It omits error behavior and whether the URL is permanent or signed, so it falls just short of fully complete for a simple 3-param read 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?

Schema description coverage is 100% and both enums are fully explained in the schema, so the baseline is 3 per the rubric. The phrase 'chosen for the background you name' loosely reinforces the theme parameter's role, but adds no syntax, defaults, or constraints beyond what the schema already documents.

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 resource (a company's logo) and the concrete form it takes (a directly embeddable image URL), which is more precise than the tool name 'logo' alone. It also explicitly differentiates itself from the sibling 'brand' tool, so an agent can select correctly without opening schemas.

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?

It states exactly when to prefer this tool over the sibling: 'Use this rather than brand when the mark is all you need,' and backs it with two concrete selection criteria (cost and payload size). This is an explicit when-to-use and when-to-use-alternative statement.

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