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

Beyond annotations, it explains precedence rules, immediate propagation, cover path constraints tied to the live version, fallback behavior, and that the result returns the actual card values WeChat fetches. This is rich behavioral context with no contradiction.

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?

The description is front-loaded with the main action and uses bullets for precedence, cover-path behavior, partial updates, and result semantics. It is appropriately sized and every bullet adds useful information.

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 mutation tool with no output schema, the description covers precedence, live-version requirements, clearing behavior, immediate effect, and returned values. An agent has enough context to invoke 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 75% and the description adds important semantics for desc, cover, and title, including null-clearing and cover-path requirements. It does not explain proposal_id, but the other parameters are well-covered.

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: changing the WeChat share card for a page, including title, description, and cover. It clearly scopes the operation to link previews in WeChat and is distinguishable from general publishing or versioning siblings.

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 gives clear operational guidance: stored per page, immediate effect, no new version needed, pass only changes, and null clears values. It does not explicitly name alternative sibling tools, but the usage context is strong.

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