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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states that only supplied fields are changed and that the platform cannot be altered, which are key behavioral traits not evident from the schema alone. It could go further (e.g., mentioning error cases or permission failures), but the essential behaviors are covered.

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 with no redundant words. The purpose is front-loaded, and the key constraint (platform immutability) is placed at the end. Every word contributes to the meaning, making it concise and well-structured.

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 relatively simple update tool with no output schema and no annotations, the description covers purpose, platform scope, partial-update behavior, platform immutability, and permission context. It omits response format and error handling, but these are less critical for a tool of this complexity, and siblings like get-account/list-accounts can supplement.

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 descriptions cover all 5 parameters (100% coverage), so the schema already explains each parameter's meaning. The description adds a general semantic note about partial updates but does not enhance any specific parameter beyond the schema. Baseline 3 is appropriate given the high schema 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?

The description states a specific verb ('Update'), a resource ('a posting account'), and explicitly lists the platforms (TikTok, Instagram, YouTube). It distinguishes itself from create/delete/list siblings by clarifying that the platform cannot be changed here and that only supplied fields are modified, making it unambiguously an update operation.

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 provides context on when to use the tool: for accounts the authenticated user is allowed to manage, and it notes the partial-update behavior ('Only the supplied fields are changed'). It does not explicitly name alternative tools (e.g., 'use create-account for new accounts') but the purpose and constraint effectively route an agent to use this for updates rather than creation or deletion.

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