wordpress_set_custom_meta

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

With no annotations, the description must disclose behavioral traits, but it only says 'Set', implying a write operation. It does not state whether it overwrites existing metadata, whether it creates new entries, what permissions are required, or what the return value is. This is a significant gap for a mutation tool.

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 a single sentence with no filler. It front-loads the action and resource, and every word earns its place. It is concise without being under-specified in terms of purpose, though it lacks behavioral depth.

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?

Given the absence of annotations, output schema, and schema description coverage, the description is insufficiently complete. It provides the basic purpose but does not cover behavioral details, edge cases, or parameter semantics, leaving the agent to infer too much.

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?

The schema has 0% description coverage, and the description does not add any meaning to postId, metaKey, or metaValue. While the parameter names are somewhat self-explanatory, the description does not compensate for the lack of schema documentation, failing to provide context for expected values or behavior.

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 'Set' and the resource 'custom post metadata field', which is specific and distinguishes it from sibling tools like set_featured_image or set_og_tags. It does not explicitly mention alternatives, but the resource is unambiguous and ownable.

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 phrase 'useful for custom fields and plugins' provides some context for when the tool is applicable, but it is vague and does not explicitly compare to alternative tools or state when not to use it. The guidance is implied rather than clearly scoped.

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