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

Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds beyond this by disclosing the return shape ({id, title, text, url, metadata}), the three entity categories, and the citation requirement ('Always cite the url'). This is meaningful behavioral context, not a repetition of annotations.

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?

Three sentences with no wasted words. It front-loads the action, then gives the id grammar, return shape, citation rule, and alternative routing in a logical order. Every sentence adds value.

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 single-parameter tool with no output schema, the description is remarkably complete: it tells the agent what ids to pass, what to expect back, and how to handle the result (cite the url). No critical decision-making information 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?

The schema has a pattern and length constraints but 0% description coverage for the single id parameter. The description compensates fully by explaining that the id must be one of the three returned forms from search and mapping the prefix to entity types. This is exactly the semantic meaning an agent needs.

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 uses a specific verb and resource ('Fetch the full content for one id returned by search') and enumerates the exact id forms accepted: rental:<uuid>, plan:<uuid>, and page:<route>. This clearly distinguishes it from sibling tools like get_rental, which is called out explicitly.

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?

It states when to use this tool: for ids returned by search that need full content. It also explicitly provides the alternative path, saying hosts that can call specific tools should prefer get_rental or the resources, which is direct and actionable.

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