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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable interpretive context beyond annotations: it includes missing/failed observations, warns that observation times differ from publication, and explicitly says null counters are not zero. This prevents a common misinterpretation of missing data as zero.

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, both informative, with the core action front-loaded and no filler. Every clause adds value: the 'including missing/failed observations' clarifies scope, and the final sentence provides a critical interpretation guard. This is a model of concise, effective description.

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 no output schema, the description covers the most important semantic caveats (null vs zero, timing differences, missing observations) that an agent could not infer from the name or schema. It does not describe the response shape or pagination behavior, but the schema provides limit/cursor expectations, so the gap is minor. Overall, sufficiently complete for correct invocation.

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 0%, and the description does not mention any of the three parameters (post_id, limit, cursor) by name or add meaning to them. It only implies the post association via 'a post’s', leaving limit and cursor entirely unexplained while the schema provides no help either. The description fails to compensate for the undocumented parameters.

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+resource ('Read a post’s stored engagement checkpoints') and adds a distinguishing detail ('including missing/failed observations') that separates it from sibling tools like get_post or get_live_summary. The scope is clear: historical engagement observations, not live or aggregate views.

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 when to use the tool: when you need stored, historical engagement observations rather than live or summary data. It does not name alternative tools explicitly, but the context ('Observation times differ from publication') signals that this is for checkpoint history, not current state. No exclusions are stated, but the usage context is clear.

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