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

Annotations already mark readOnly/idempotent/openWorld, and the description adds meaningful context: explains what a mint is, why buying is beneficial, and what each result includes (conclusion, list_price_usdc, attestation). No contradiction with annotations.

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 tight paragraphs: first sentence states purpose, second gives economic rationale, third describes return shape. Zero wasted words; every sentence adds value.

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?

Given an output schema exists, the description adequately covers the return shape, the value proposition, and the next step. It does not discuss pagination or empty-result behavior, but those are minor for a search 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 high (80%), so the baseline is 3. The description adds the 'fingerprint' concept linking model_family and cutoff_quarter, but does not explain limit or cluster_id beyond what the schema already provides.

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 opens with a specific verb ('Search') and identifies the resource ('Fillin marketplace') and object ('minted data + reasoning assets'). It clearly distinguishes itself from siblings like fillin_buy_mint by mentioning paying via that tool, making the search-vs-purchase relationship explicit.

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?

Provides clear context for when to use the tool: finding mints that are often cheaper than re-running retrieval/reasoning. It also points to a follow-up action (verify attestation then use fillin_buy_mint), but does not explicitly name alternative discovery tools (e.g., fillin_query) or state when not to use it.

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