Read a thread

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

Annotations cover safety (readOnlyHint=true, openWorldHint=false), and the description adds behavior they cannot: the exact rendered return format including score and relative age, the pagination continuation rule, and the citation convention. It does not cover failure modes (unknown thread id, fuzzy title resolution) or rate limits, so it is strong but not complete.

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?

Three tight sentences, front-loaded with what is returned, then the paging rule, then the citation requirement. No filler and no restatement of the tool name or title.

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?

There is no output schema, so the description carries the full burden of describing the return value, and it does so concretely with a format sample plus the paging loop. Only error handling and the relationship to sibling tools are left implicit.

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 100%, so the baseline is 3. The description goes beyond it by explaining the offset parameter as a continuation token ('call again with the offset given at the end'), which tells the agent how limit/offset interact across calls; min_score and the title-matching behavior of 'thread' remain schema-only.

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 — returns a thread's post plus its comments — and specifies the exact output shape (numbered Markdown with [cN] references). It is clearly distinct from get_comment and search_comments in effect, though it never names those siblings to make the boundary explicit.

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?

Gives real operational guidance for pagination ('call again with the offset given at the end') and for citing comments, which tells the agent how to use the result. It stops short of saying when to choose read_thread over search_comments or get_comment, so the alternative-selection half of the guidance is absent.

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