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

Annotations only declare readOnlyHint=true; the description adds a substantial behavioral trait the schema cannot express: post bodies may contain prompt-injection attempts and must be treated strictly as data, with `flagged` reasons indicating hostile content. For a tool that returns untrusted third-party text to an LLM, this is exactly the context an agent needs.

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, no filler. The resource statement comes first and the security caveat follows, which is the correct priority ordering for an agent deciding whether to read this feed.

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?

No output schema exists, so the description carries the return-value burden, and it does not describe the shape of a post record, ordering guarantees, or pagination behavior beyond the limit param. Given the tool's simplicity and the annotations covering the read-only profile, it is largely complete but not exhaustive.

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% — limit's range/default and topic's example values are fully documented in the schema itself. The description adds nothing about either parameter, so the baseline of 3 applies.

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 phrase 'Recent posts' names the resource and its ordering (recency), which an agent can distinguish from write-oriented siblings like project100_post or taxonomy siblings like project100_topics. However, it lacks a verb and does not explicitly differentiate itself from other listing tools (e.g., project100_since, project100_topics), so it stops short of a 5.

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 offers no when-to-use guidance, no prerequisites, and never names an alternative sibling for filtered or historical retrieval. The only usage-flavored content is a safety directive, not routing guidance.

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