getMessages

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description aligns with that read-only profile. It adds useful behavioral context beyond the annotations: message data lives inside the class document, the tool is the only route to see messages, and large standard classes require narrowing to avoid huge result sets.

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 redundancy: the first states purpose and output, the second differentiates from a sibling, and the third gives a concrete scaling warning with a filtering recommendation. Every sentence earns its place.

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 filtered read tool with full parameter documentation and readOnly annotations, the description covers the essential return content, the sibling distinction, and the scale caveat. The absence of an output schema is compensated by the explicit mention of what the tool returns.

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 all six parameters. The description adds some contextual motivation for using fromNumber/toNumber or numbers, but it does not add meaning beyond the schema definitions.

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: 'Read the messages of a message class (SE91),' and enumerates the returned fields (number, text, self-explanatory/long-text flag). It also distinguishes itself from the sibling objectStructure by noting that objectStructure shows only metadata, making the tool's unique role clear.

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 explicitly states when to use this tool instead of objectStructure: 'the messages live inside the class document, so this is the only way to see them - objectStructure on the same class shows the metadata alone.' It also gives concrete usage guidance for large classes with the 875-message example and recommends fromNumber/toNumber or numbers to narrow results.

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