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

The key behavioral detail 'Unspecified values are preserved' is disclosed, which is important partial-update semantics not captured by annotations. With destructiveHint already signaling mutability, this adds useful context without over-claiming safety.

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 purposeful sentences with no filler. The primary action is front-loaded and the critical preservation behavior is stated immediately after.

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 two-parameter update tool with full schema coverage, an output schema, and annotation coverage, the description is sufficient for an agent to call it correctly. It tells the agent what to do, what to check first, and how partial updates behave.

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%, but the description adds meaningful semantic value by noting that updates are partial and unspecified values are preserved. This clarifies how the values parameter behaves beyond the schema's JSON-object description.

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?

Description states a specific verb and resource: update one or more theme setting values for a blog. It is clearly distinguishable from siblings like get_theme_settings, switch_theme, and update_theme_file.

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 a clear prerequisite: use get_theme_settings first to discover valid keys. It does not explicitly rule out alternatives, but the tool name and resource target make the intended use obvious.

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