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

With no annotations, the description carries the full burden. It discloses authentication requirements, platform list, and character limit for X. However, it does not mention error handling, idempotency, or whether posting overwrites existing content.

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 plus a concise code example. All information is front-loaded: purpose, prerequisite, platforms, call format. No wasted words.

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 posting tool with 4 parameters and no output schema, the description covers purpose, auth, platform list, and example. However, it lacks information about the return value or error cases, which would be helpful given no output schema.

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% with parameter descriptions. The description adds value beyond schema by explaining the auth requirement, listing supported platforms, and providing a call format example. This compensates for the schema's minimal descriptions.

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 content as a Presence identity on a given platform', specifies the resource, and lists specific platforms. This distinguishes it from sibling tools like presence_act, presence_reply, etc.

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 mentions a prerequisite: 'Requires an attached session with valid auth cookies.' It also provides a list of supported platforms and an example call format. However, it does not mention when not to use this tool or alternatives.

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