Threads MCP Server

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

No annotations are provided, so the description carries full burden. It states the tool retrieves ancestors but doesn't disclose behavioral traits such as whether it's read-only, potential errors (e.g., invalid entityId), output format, or if it includes the root entity. For a tool with no annotations, this leaves significant gaps in understanding its operation.

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 a single, efficient sentence that front-loads the core purpose ('Get all ancestors of an entity') and adds clarifying context ('path to root'). There is no wasted language, making it easy to parse and understand quickly.

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 complexity of hierarchical data retrieval and the lack of annotations and output schema, the description is incomplete. It doesn't explain what 'ancestors' entails (e.g., ordered list, includes self), potential limitations, or error cases. For a tool in a set with many siblings, more context is needed to ensure correct usage.

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%, with the parameter 'entityId' documented in the schema. The description adds no additional meaning beyond implying it's used to identify the starting entity. Since the schema fully describes the parameter, the baseline score of 3 is appropriate, as the description doesn't compensate but doesn't detract either.

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 'Get' and the resource 'ancestors of an entity', specifying the action and target. It distinguishes from siblings like 'get_children' or 'get_subtree' by focusing on upward traversal. However, it doesn't explicitly mention what 'ancestors' means in this context (e.g., parent chain vs. lineage).

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 is provided on when to use this tool versus alternatives like 'get_full_tree' or 'get_subtree'. The description implies usage for retrieving upward paths but doesn't specify scenarios, prerequisites, or exclusions. Without context, an agent might struggle to choose between similar hierarchical tools.

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