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

Annotations cover safety (readOnlyHint=false, destructiveHint=false), but the description adds the critical non-annotated behavior: the call SPENDS the user's coins, price-change protection, idempotency expectations, privacy ('logos stay private to the account'), and asynchronous polling. This is exactly the behavioral context an agent needs before invoking a paid mutation.

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?

Roughly three dense sentences, front-loaded with purpose, then cost behavior, then next steps. No filler; every clause carries an actionable fact (cost, guard, privacy, polling, follow-on tool).

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 compensates well by telling the agent to poll get_logo for the image and mentioning the build_brand_kit follow-on. It does not explicitly state what create_logo itself returns (e.g. a logo id), but the workflow implies it and leaves little ambiguity.

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; the description goes further by tying expected_total and model to list_logo_models and mapping the brief components to parameters. It adds workflow linkage rather than raw field definitions, which is genuinely useful even if the schema already documents each field.

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 ('Design a logo from a brief') and enumerates the brief inputs (brand name, mark depiction, type, style, detail, colours), so an agent knows exactly what the tool produces. It is clearly distinguishable from siblings like get_logo (retrieval) and build_brand_kit (asset packaging).

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 routes the workflow: get coins from list_logo_models and pass them as expected_total, poll get_logo for the finished image, and use build_brand_kit for the asset pack. It also names a key precondition/guard ('if the price changed, nothing is spent').

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