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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the key behavioral nuance that there is no time filtering, which is useful. However, it doesn't mention pagination, ordering details beyond 'most recently saved', or what happens when limit exceeds max, though the schema covers the max. This is adequate but not rich.

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, front-loaded with the core function and the key caveat (no time filter), followed by a clear routing instruction. Every sentence earns its place with zero waste.

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 list tool with one parameter and full schema coverage, the description is nearly complete. It covers the core behavior, the caveat, and the alternative. The only minor gap is that it doesn't describe the return format, but with no output schema and a simple list operation, this is a small omission. The annotations cover safety, so nothing critical is missing.

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%, so the schema already documents the limit parameter with default and max. The description adds the meaning of 'limit' as 'N most recently saved posts' but doesn't add significant new semantics beyond the schema. Baseline 3 is appropriate.

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's function: retrieving the N most recently saved posts, with an explicit clarification that there is no time filter. It also distinguishes itself from search_posts, which is a sibling tool, by naming it directly and explaining the difference.

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 explicitly says when to use this tool (for recent saves without time bounds) and when not to use it (for time-bounded queries), and names the alternative (search_posts with time_filter). This is exactly the kind of routing guidance an agent needs.

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