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

With no output schema, the description carries the full burden and does so: it documents the exact returned fields, null semantics ('null when LinkedIn did not return it'), the engagement_rate threshold behavior under 100 impressions, latency ('LinkedIn can lag by a few hours'), lifetime-vs-window scope, and the needs_reconnect permission failure mode with its remedy. This is far beyond the readOnly/openWorld annotations.

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?

Front-loaded with the core resource and metrics before the caveats, and nearly every clause carries distinct information. The field inventory is dense but justified given the absence of an output schema; only minor overlap with the schema's id 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 single-post stats tool with no output schema, the description covers return fields, null handling, freshness, permission failures, and eligibility. An agent has everything needed to call it and interpret results 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 coverage is 100% for the single id parameter, so the schema already documents that it must come from list_posts with status sent. The description only restates that constraint by noting that sent posts are the ones with statistics, adding no new syntax or format detail.

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 (reads) and resource (engagement for one published post) and enumerates the exact metrics returned, which cleanly separates it from account-level siblings like get_insights. An agent can distinguish it from every sibling without opening a schema.

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 a hard usage precondition ('Only posts with status sent have statistics') and implicitly routes comparative/account analysis to get_insights. It never states an explicit when-not or names get_insights as a formal alternative, so it stops short of full routing guidance.

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