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

The description adds real value beyond the annotations: a [WRITE] marker, the mandatory confirm:true gate, and the return shape (media id and URL). It does not discuss idempotency or failure behavior, but the safety profile is well covered by both annotations and text.

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?

Three compact clauses with the [WRITE] tag and the core action front-loaded. Every sentence contributes scope, source, return value, or the confirmation gate.

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 7-parameter write tool with no output schema, the description still covers the write nature, the confirmation requirement, and the return value, while annotations and schema cover the rest. Only edge cases like size limits live purely in the 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 description coverage is 100%, so parameters such as url, post_id, alt_text and filename are already fully documented. The description only echoes the confirm requirement, which is the correct baseline when the schema carries the load.

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?

States a specific verb (upload) and resource (WordPress media library), plus the accepted source (a public URL) and file types. It is clearly distinguishable from siblings such as wordpress_create_draft or wordpress_publish, which also write content.

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?

'from a public URL (for example an image you just generated)' gives concrete context for when to reach for this tool, and 'Requires confirm:true' signals the prerequisite. No explicit exclusions or named alternatives are given, but the relevant workflow is clear.

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