domain_filter

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 specifies the maximum limit of 20 domains, persistence across searches until cleared, and the effect of actions ('allow' prioritizes, 'block' excludes). It lacks details on error handling or rate limits, but covers essential operational constraints.

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 appropriately sized and front-loaded, with every sentence adding value: the first states the purpose, the second explains usage with examples, and the third covers constraints and persistence. There is no wasted text, making it efficient and well-structured.

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 (2 parameters, no output schema, no annotations), the description is largely complete: it explains what the tool does, how to use it, and key behaviors. It could improve by mentioning the tool's relationship to siblings like 'clear_filters' or expected output, but it adequately covers the core functionality and constraints.

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 both parameters fully. The description adds minimal value beyond the schema by reinforcing the purpose of 'allow' and 'block' actions, but does not provide additional syntax or format details. This meets the baseline for high schema coverage.

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 tool's purpose with specific verbs ('configure domain filtering') and resource ('search results'), distinguishing it from siblings like 'clear_filters' and 'list_filters' by focusing on configuration rather than management or listing. It specifies the exact function of setting up domain-based filters.

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 provides clear context on when to use this tool (e.g., to prioritize trusted sources or exclude unreliable ones) and mentions persistence across searches, but it does not explicitly state when not to use it or name alternatives like 'recency_filter' for other filtering needs. Usage is implied but not exhaustively defined against all siblings.

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