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

Annotations declare non-readonly, non-idempotent, non-destructive. The description adds genuinely useful context beyond them: that only a draft is created (no immediate publishing), that media URLs must be publicly accessible, and that user approval is required. It doesn't address re-invocation/idempotency behavior, so not a full 5.

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-loads the core action, then sequences constraints and follow-up tool calls. Four sentences, each earning its place. Tight and readable, though slightly dense with three separate tool callouts.

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 10-parameter tool with nested objects and no output schema, the description covers the critical workflow (draft-only, media prep, approval, publish path). Remaining parameter detail is well handled by the 80%-covered schema, so an agent can 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 description coverage is 80%, so the schema already documents most parameters including postType requirements and platform limits. The description adds only the publicly-accessible-URL constraint on media, which the schema does not state. Baseline 3 for schema-driven coverage.

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 (Create) plus resource and scope (text, image, or carousel post draft). It cleanly distinguishes itself from siblings like createStory, createVideo, and publishPost without needing their schemas.

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?

Explicitly routes the agent: call createUploadLink first for local files, ask the user to approve destination/timing before scheduling, and call publishPost for immediate publishing. Names the alternative tools and the conditions that select them.

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