Read DM messages

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the description's job is to add context — it does so with result ordering ('newest first') and the hard cap tied to Instagram's own limit. It omits any note on pagination or rate limits, but with no pagination parameters in the schema that gap is small.

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?

Two short sentences: scope and ordering first, prerequisite second. Nothing repeats the annotations or the schema verbatim.

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 simple read-only lookup with no output schema and one required parameter, this covers what an agent needs to invoke it. It could say more about what a returned message contains (sender, timestamp, media), but the response_format option is already documented in the schema.

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 only 33% and only response_format is documented there, yet the description supplies real meaning for limit (why 20 is the ceiling) and for conversation_id (its source tool). The pattern constraint on conversation_id remains unexplained, keeping it short of a 5.

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 ('Read ... messages in one DM conversation') plus scope ('latest', 'up to 20') and ordering ('newest first'), which cleanly separates it from ig_list_conversations and ig_send_message.

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?

Explicitly tells the agent where the required conversation_id comes from ('Get conversation IDs from ig_list_conversations'), a real prerequisite. It stops short of stating when not to use it (e.g., use ig_list_conversations to browse threads first, or ig_send_message to respond).

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