Read a thread

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds the returned-content scope (ancestors plus replies), which is useful, but says nothing about pagination, truncation at depth limits, or rate behavior. With annotations carrying the safety profile, this is adequate but not rich.

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 sentences, zero filler. The scope-defining clause comes first and the usage directive follows, so the agent gets purpose before guidance.

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 tool with full schema coverage and a complete annotation set, the definition covers purpose, input format and usage timing. Since there is no output schema, a sentence sketching the shape of the returned thread (e.g., root/post/parent/replies fields) would have closed the remaining gap.

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 uri, depth, account and parent_height are already documented in the schema, including the at:// / bsky.app link forms and defaults. The description adds no parameter detail beyond that, which is the correct baseline 3 when the schema does the heavy lifting.

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 uses a specific verb ('Read') and defines the resource precisely: a post plus 'everything above it and the replies below.' That scope statement inherently differentiates it from siblings like get_feed, get_quotes, or get_post_likes, which return different slices of conversation graph.

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?

It gives explicit usage timing: 'Use this before replying, so the reply lands with context.' That is clear context for when to call it. It does not name alternatives (e.g., get_quotes for quote posts, search_posts) or state when-not to use it, so it stops short of a 5.

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