search_crates

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

With no annotations provided, the description carries the full burden and does well by disclosing key behavioral traits: it describes the return format ('multiple matching crates with names, versions, descriptions, download counts, and URLs'), mentions default and maximum values for the limit parameter, and provides an example of what results look like. It doesn't mention rate limits or authentication requirements, but provides substantial operational context.

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 well-structured with clear sections (purpose, usage guidelines, parameters, returns, example) and every sentence adds value. It's appropriately sized for a search tool with 2 parameters and no annotations, with no redundant information.

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 the tool's moderate complexity (search operation with 2 parameters), no annotations, and no output schema, the description provides substantial context: clear purpose, usage guidelines, parameter details, return format description, and an example. It could potentially mention error cases or pagination, but covers the essential operational context well.

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 0%, so the description must compensate. It successfully adds meaning for both parameters: it explains that 'query' accepts 'search keywords' with concrete examples ('http client', 'web framework'), and specifies that 'limit' has a default of 5 and maximum of 100. This goes well beyond what the bare schema 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 clearly states the specific action ('Search for Rust crates on crates.io') and resource ('by name or keywords'), distinguishing it from sibling tools like search_docker_images or search_gcp_services by specifying the Rust/crates.io domain. It explicitly mentions the verb 'search' and target 'Rust crates'.

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 includes explicit 'USE THIS WHEN' and 'BEST FOR' sections that provide clear context for when to use this tool ('to find Rust packages/crates for a specific purpose or library' and 'discovering which Rust crates exist'). It also names specific alternative tools to use after finding a crate (crates_metadata, WebFetch for docs).

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