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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description goes beyond that by disclosing the pricing model ($0.05/call via x402 USDC on Base), the alternative auth path (Tensorust key), and the difference in return content between free and paid tiers. Missing is what happens on payment failure or whether the x402 terms are returned as an error-like response.

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 dense sentences with the core action front-loaded and no filler. The pricing details are compressed but jargon-heavy (x402, USDC on Base) and partly duplicate the schema's `full` description, which slightly undercuts efficiency.

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 carries the burden of describing returns, and it does so at a useful level: 'card', 'counts and previews', 'every linked object and property'. Combined with the pricing/auth disclosure, an agent has enough to call it correctly; only error and payment-failure behavior is unaddressed.

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 50%, with `id` undocumented in the schema but explained in the description via concrete prefixed examples, which is real added meaning. The `full` explanation largely repeats the schema text, and the cost/auth implications are the genuinely new part.

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 ('Expand') and resource ('ontology id ... into its card') and gives three concrete id-format examples (org:, cg:, rule:), so an agent can recognize valid input. It does not explicitly distinguish itself from sibling lookup_organization or search_organizations, which keeps it from a 5.

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 does give a clear when-to-use signal for the `full` flag: omit for free preview, set true for every linked object and property. However, there is no guidance on when to choose this tool over lookup_organization or search_organizations, which is the main ambiguity an agent would face given the sibling set.

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