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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds meaningful behavioral context by explaining how results are ranked (editorial-mode match, plumb, source affinity, recency) and that they come from the same section, which goes beyond the annotation. It does not detail error handling or pagination, but for a read-only tool with a simple input schema, this is adequate.

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, focused sentence that states the core purpose upfront and then provides ranking details. It is efficient and free of redundancy, though it could be slightly more structured (e.g., separating the purpose from the ranking criteria) for even faster parsing, but it is well within the 'appropriately sized' range.

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 simple read-only tool with two parameters (one required) and no output schema, the description provides sufficient context: it explains what the tool does, how results are determined, and the scope (same section). It does not mention return format or potential errors, but given the low complexity and the presence of readOnlyHint, the agent has enough to call it correctly and interpret the outcome.

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% for both parameters, with id described as 'The source story id' and limit as 'Max related stories (default 4, max 12)'. The description does not add new parameter meaning beyond confirming id refers to the article; it does not elaborate on limit semantics or edge cases. Since the schema fully documents the parameters, the description provides no incremental value, aligning with the baseline score of 3.

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 tool returns related stories for a given article, specifying the resource (BedrockNews stories) and the action (retrieve related). It distinguishes itself from siblings like get_article by focusing on relatedness, and adds ranking criteria (section, editorial-mode match, etc.) that make its purpose unambiguous.

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 implies usage ('for a given article') but does not explicitly contrast with alternatives or state when not to use it. It provides clear context (same section, ranked) but lacks exclusions or explicit comparison to sibling tools like list_stories or get_extraction_graph, leaving the agent to infer when this tool is the best choice.

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