Read a thread

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

Annotations already indicate read-only, idempotent, and non-destructive behavior, so the description does not need to restate safety. It adds useful context about returning ancestors and replies, but it says 'everything above it' without acknowledging the parent_height/depth limits, and it does not describe output ordering or truncation behavior.

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 three short sentences with no wasted words. It front-loads the core behavior, then adds accepted input forms, then gives the practical usage context.

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 read-only tool with full parameter documentation, annotations for safety, and no output schema, the description explains what will be returned (post, ancestors, replies) and the canonical use case. An agent has enough information to select and invoke the tool 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 description coverage is 100%, and all four parameters are documented with meaningful descriptions. The tool description adds little beyond restating that the URI can be an at:// URI or bsky.app link, so the schema carries the parameter-semantics burden.

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 identifies the operation as reading a post plus its surrounding conversation, and it explicitly defines the scope as everything above the post and replies below it. This distinguishes it from sibling read tools like get_timeline, get_author_feed, and get_post_likes.

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 gives an explicit use case: 'Use this before replying, so the reply lands with context.' This tells the agent when to invoke the tool, though it does not mention when not to use it or name alternative tools.

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