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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description adds meaningful non-obvious behavior: the tool does not invoke the paid agent, cursor pagination does not re-run the search, and topic priority values map to specific integers. These details go beyond the structured annotations and help the agent predict behavior accurately.

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 compact and front-loaded: purpose first, then read-only/exclusion, then usage mechanics, priority detail, and skill prerequisite. Every sentence contributes distinct information, and there is no filler or repetition of the tool title.

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?

Even without an output schema, the description explains what comes back—matching rows, pagination via cursor, and priority values—and points to the required skill for deeper context. Combined with the rich parameter schema and annotations, the agent has enough information to invoke the tool correctly in a first attempt.

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 baseline is 3, but the description adds value by explaining the question-or-cursor usage pattern and spelling out the priority integer mapping. It reinforces the schema's guidance on columns and pagination without repeating every schema detail, though it does not add much about limit or column validation beyond what the schema already 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 opens with a specific verb and resource: 'Answer a natural-language question about your Modem data and get matching rows back.' It clearly differentiates itself from the agent tools by stating it is read-only and 'does not run the full Modem agent or spend agent credits.' This makes the tool's role unambiguous relative to siblings like modem_agent_invoke.

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 gives explicit when-to-use context—natural-language data questions—and a clear exclusion: it does not run the full Modem agent or spend credits, so agents know not to use it when agent execution is needed. It also provides a prerequisite: 'Before your first call, read the skill: modem_skills({ name: "search-modem" })'.

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