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

Annotations already declare readOnlyHint and non-destructive, so the safety profile is covered. The description adds what annotations cannot: that results are paged and that an empty query returns the entire repository (a potentially large response the agent should anticipate).

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?

Four dense sentences, each carrying distinct information (query semantics, filter/dist/arch interplay, return format, endpoint). No filler and the core behavior is front-loaded.

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 by noting the shape of returned items and pagination. It stops short of describing default page size behavior or error conditions, but an agent has enough to invoke it correctly.

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 earns a fourth point by stating a cross-parameter rule not present in the schema: 'arch applies to Alpine/RPM/Debian only', plus the dist-overrides-filter precedence.

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 and resource ('search a repository by package file name') and names the sibling whose output format it mirrors ('Items carry the same ready-made URLs as list_packages'). It doesn't explain why an agent would pick this over list_packages, but the purpose is unambiguous.

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?

Gives an operational hint that an empty q returns every package, which implies the tool doubles as a bulk-list, but never says when to use it versus list_packages or get_package. Usage is implied rather than stated.

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