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

Beyond the annotations, it discloses that the tool is deterministic, offline, calls no model, and runs no appraisal, and it describes the interpretation.source field and the 'words not used' feedback. That is real behavioral context the annotations do not carry, though return format is partly covered by the output 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?

Front-loaded with the core purpose and routing outcome; every sentence carries information (routing, alternatives, determinism, appraisal note). It is dense but not padded, though a single long paragraph makes it slightly harder to scan.

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?

Covers what the tool does, when to use alternatives, the deterministic/offline nature, and the returned interpretation metadata; with an output schema present, no further return-value detail is required. Nothing an agent needs to invoke it correctly is missing.

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% and there is only one parameter, so the schema already documents 'question' with the 300-char limit. The description reinforces the expected sentence form with an example but adds no syntax beyond what the schema provides, so the baseline 3 is appropriate.

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 ('Answer one plain-English sentence about the domain market') and immediately distinguishes itself by naming the two sibling tools it routes to. An agent can tell it apart from search_domain_listings and search_recorded_sales without opening any schema.

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?

Explicitly says to use search_domain_listings or search_recorded_sales instead 'when you already have exact filters,' giving both the alternative and the selecting condition. It also maps question types to outcomes, so the agent knows what input shape to send.

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