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

Annotations cover the safety profile (openWorldHint, idempotentHint, destructiveHint=false), and the description adds real operational context beyond them: external HTTP requests per due entry, YAML backend writes, the exact idempotency key ('already-published (content.id, channel) pairs are skipped'), and the no-op case. Cron-safety is also disclosed explicitly.

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?

Three sentences, front-loaded with the action, then side effects, then routing. Every sentence carries distinct information (what it does, what it touches, when to pick it over alternatives) with no repetition.

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?

An output schema exists, so return values need not be explained. For a single-optional-parameter trigger tool, the description supplies the side effects, idempotency semantics, failure-relevant behavior, and sibling routing an agent needs to call it 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% and the single 'now' parameter already documents its ISO-8601 format and default behavior. The description only echoes 'the given time boundary' without adding format or edge-case detail, so the schema does the heavy lifting and the baseline 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 description states a specific verb and resource with precise scope: 'Fire all scheduled posts due at or before the given time boundary.' The routing sentence separates it from post_publish/post_schedule (adding content) and post_status (inspecting results), so 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?

It explicitly says when to use it ('on a recurring schedule to flush the queue') and names the alternatives for adjacent jobs ('use post_publish or post_schedule to add new content; use post_status to inspect results'). Both the trigger and the exclusions are stated, leaving nothing to inference.

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