alt_search

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

No annotations are provided, so the description carries the full burden. It discloses that only live listings are returned, that it is credential-free public data, and that it searches an aggregator index across multiple sources. It also names the sibling for completed sales. It doesn't mention pagination limits or rate limits, but for a read-only search tool with no annotations, the key behavioral traits (live-only, credential-free, aggregated) are disclosed. A 4 is appropriate because it adds meaningful behavioral context beyond the schema.

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?

The description is a single dense paragraph that front-loads the core purpose and then adds scoping details. It's longer than the ideal two-sentence example, but every sentence earns its place: the source list, the live-only constraint, the credential-free note, and the pointer to alt-categories all add value. It loses one point for being somewhat long and for the slightly awkward 'its search carries' phrasing, but it is well-structured and information-dense.

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?

For a search tool with 8 optional parameters, 100% schema coverage, and no output schema, the description covers the key contextual gaps: what the aggregator includes, that only live listings are returned, that it's credential-free, and where to find accepted enum values. It doesn't describe the return format or pagination behavior, but the schema documents page/per_page defaults and max. The pointer to alt-categories for accepted values is a strong completeness signal. A 4 is justified; a 5 would require return-format or pagination behavior disclosure.

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 schema already documents all 8 parameters. The description adds context by explaining the free-text query scope ('item name, subject, brand, and variety') and that omitting q or passing * browses everything, which is in the schema. It also clarifies that listing_type and auction_house are comma-separated filters, which the schema already states. The description doesn't add much beyond the schema, but it does reinforce the aggregator semantics. Baseline 3 is correct.

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 ('Search'), a precise resource ('Alt's aggregated card marketplace' / 'universal aggregator index'), and enumerates the exact sources (eBay, Fanatics Collect, Pristine Auction, Goldin, CardHobby, Memory Lane). It also distinguishes itself from alt-sold-listings by explicitly noting only live listings are returned. This is a clear, specific purpose that differentiates it from sibling tools.

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?

The description explicitly says when to use this tool ('Search Alt's aggregated card marketplace... by free-text query, category, source auction house, grading company, and listing type') and when not to ('Only currently-live listings are returned; see alt-sold-listings for completed sales'). It also points to alt-categories for accepted enum values, giving the agent a clear routing path. This is explicit when/when-not guidance.

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