Read a whole conversation

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

Annotations already mark it read-only and idempotent; the description adds meaningful behavioral detail beyond that: messages are oldest-first, HTML is only returned under certain conditions, attachment metadata and truncation flags are included, and large threads can be resource-heavy. No contradiction with 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?

Every sentence earns its place: core behavior, ordering, reply workflow, and performance guidance. It is dense but well-structured and front-loaded with the most important information.

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 there is no output schema, the description compensates by specifying what messages contain, the ordering, truncation behavior, and the reply workflow. For a read-only tool with rich annotations, this is complete enough for an agent to select and invoke it correctly.

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 coverage is 100%, so the baseline is 3, but the description adds operational meaning: max_body_chars applies per message and should be lowered when only the gist is needed, and include_html only matters when a text body already exists. This goes beyond the schema's descriptions.

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: 'Fetches a conversation with every message' decoded like get_message. The scope (whole conversation vs. individual message) is clear and distinguishes it from the sibling get_message without opening schemas.

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?

Provides clear practical usage context, including how to reply using the last message's IDs, and when to lower max_body_chars for large threads. It does not explicitly state when not to use this tool versus alternatives like get_message or list_threads, so it stops short of a 5.

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