Post a story

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds no behavioral context beyond 'post' — it does not disclose that this is a mutating action (though implied), that it posts publicly to followers, that media must be accessible, or any side effects. The idempotencyKey is explained in the parameter schema, not the description, and the description adds nothing about retry semantics.

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?

A single sentence that front-loads the action and concisely lists the supported story types. No superfluous words, and it captures the core functionality effectively.

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?

The description covers the essential use cases (text/media with optional caption) and is sufficient for a caller to understand the tool's purpose. It omits some details like the requirement for accountId (covered in schema) and the idempotency mechanism (covered in parameter description). With no output schema, the description provides adequate context for correct invocation.

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%, establishing a baseline of 3. The description adds semantic value by explaining the relationship between text and backgroundColor (colored background) and between media and caption, which is not fully explicit in the schema. It clarifies the three modes of operation, aiding parameter selection.

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 action ('Post a story') and the resource type, and specifies the three supported formats: text with colored background, or image/video from a public URL with optional caption. It distinguishes this from sibling messaging tools (send_text, send_media) by focusing on the story context and the account-level action.

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 implies usage for posting stories rather than sending messages, but it does not explicitly say 'use send_text for messages' or provide alternative routing. It relies on the resource type to separate from siblings. There is no mention of when not to use this tool or prerequisites like account availability.

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