Get Messages

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read. The description adds little beyond the annotations; it says 'retrieves messages' but doesn't describe pagination behavior, default ordering, or that it may return only messages not yet deleted. No contradiction found.

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 concise—one short sentence—and the parameter filter examples are helpful and well-structured. It is front-loaded with the core purpose. It could be slightly more informative, but it earns its place with no redundancy.

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?

Given the presence of an output schema and rich annotations, the description doesn't need to explain return values. However, it lacks explicit guidance on how the message_filter syntax interacts with other parameters, pagination behavior, and required parameter semantics. It is minimally viable but not fully complete for an agent to call it with confidence in edge cases.

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 only 20%, so the description carries some burden, and it lists the main filter field and its supported syntax in detail (createTime and thread.name examples). However, it does not explain required parameters like user_google_email or space_id beyond their names, nor the order_by and page_size defaults. The filter details add real value over the schema, but gaps remain.

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 'Retrieves messages from a Google Chat space' uses a specific verb + resource and communicates the primary scope. It distinguishes itself from Gmail siblings by explicitly naming Google Chat, but does not differentiate from sibling tools like send_message, search_messages, or list_spaces, though the list verb is 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?

No guidance on when to use this tool vs alternatives such as search_messages or get_gmail_messages_content. It doesn't state exclusions, prerequisites, or conditions. The only context is that it is Chat-specific, which is implied but not explicitly routed.

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