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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety bar is met structurally. The description adds genuinely new operational context: no plan gate ('all plans'), and the important behavioral caveat that docs coverage lags the product, so empty results are not evidence of missing capability.

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 verb, resource and return type, then scoping and caveats. Dense but each sentence carries distinct information; the parenthetical URL and 'SCOPE' label are slightly heavy for the payload but not wasteful.

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?

For a one-parameter search tool with no output schema, the description covers what is returned (quotable article text), what an empty result means, and where to go for authoritative capability data. Nothing needed to call 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?

Single parameter with 100% schema description coverage ('Keywords or short phrase... max 300 chars'), so the schema already documents syntax and limits. The description adds no further query-shaping guidance beyond the example question forms, which is baseline-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 ('Searches the Onplana docs (docs.onplana.com)') plus the return shape ('article excerpts... readable step-by-step article text'). It explicitly distinguishes itself from the sibling lookup_help_topic, which returns navigation paths rather than article bodies.

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 concrete question shapes that select this tool ('how do I X', 'explain Y', 'what does Z mean') and names the alternative (lookup_help_topic) with the property that differentiates it. It also routes the agent to describe_capabilities for capability questions, and warns that an empty result means no article matched rather than a missing capability.

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