Read a conversation

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds genuinely new behavioral facts beyond those: results are newest-first and Meta caps at the 20 most recent. It does not disclose whether older messages are reachable by any means, which is the one trait an agent most needs to know.

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?

A single front-loaded sentence with no filler; the ordering and cap are stated up front. It is slightly telegram-style rather than a complete clause, but nothing is wasted.

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?

With no output schema, no annotations gap, and only 33% parameter coverage, the description should say more about what a returned message contains and how to obtain a conversation_id. The 20-message ceiling is the key constraint and it is present, so the definition is adequate but not complete for a 3-parameter tool.

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 33% — only the account parameter is documented. The description partially compensates for limit by explaining the 20-most-recent ceiling, but the required conversation_id has no format or provenance guidance in either the schema or the description, leaving the most important parameter underspecified.

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 names the resource precisely ('Messages in one Direct conversation') and its ordering, and the title supplies the verb ('Read'). It is clear what the tool returns, but it never distinguishes itself from the adjacent siblings list_conversations and send_dm, so the agent must infer the boundary between listing conversations and reading one.

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?

Usage is only implied: the phrase 'one Direct conversation' suggests a single-thread fetch versus list_conversations, but there is no explicit when-to-use, no note that a conversation_id must first come from list_conversations, and no mention of send_dm as the write counterpart. An agent can guess correctly, but the description does not route it.

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