Threads MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states this is a listing operation with filtering, but doesn't describe whether this is a read-only operation, what permissions might be required, whether results are paginated, what the default sort order is, or what happens when no filters are applied. For a tool with 4 parameters and no annotation coverage, this leaves significant behavioral questions unanswered.

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 extremely concise at just 5 words, front-loading the core purpose ('List containers') followed by the key capability ('with optional filtering'). There's zero wasted language or redundant information, making it efficient for quick comprehension.

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 listing tool with 4 filtering parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain what a 'container' represents in this context, what fields are returned, whether results are limited/paginated, or how this differs from similar sibling tools. The minimal description leaves too many contextual questions unanswered for effective tool selection and use.

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 all parameters are documented in the schema. The description adds minimal value by mentioning 'optional filtering' but doesn't provide additional context about how filters combine (AND/OR logic), filter precedence, or practical examples of when to use each parameter. This meets the baseline for high schema coverage but doesn't enhance understanding beyond what the schema provides.

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 clearly states the verb ('List') and resource ('containers'), making the purpose immediately understandable. However, it doesn't distinguish this from sibling tools like 'get_container' (singular retrieval) or 'get_full_tree' (hierarchical view), which would require more specific language about scope or output format.

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 mentions 'optional filtering' but provides no guidance on when to use this tool versus alternatives like 'get_full_tree' (for hierarchical data) or 'search_threads' (for thread-specific searches). There's no mention of prerequisites, performance considerations, or typical use cases for listing versus retrieving individual containers.

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