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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation profile is covered. The description adds 'Writes-gated', a genuine constraint not present in annotations, but never explains what gating means or that wp_enable_writes must run first, so the added value is thin.

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 tight sentences and a version tag, front-loaded with the action and example before the prerequisite. Nothing is padded, though the trailing version/connector note is metadata of limited use to an agent choosing the tool.

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 3-param, fully-described schema with annotations covering the safety profile and no output schema, the description supplies purpose, an example, and the source of valid locations. The only real gap is leaving 'writes-gated' unexplained for an agent that may need to enable writes first.

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%; every parameter (site_id, location, menu_id incl. '0 to clear') is already documented in the schema. The description's mention of sourcing locations from wp_list_menu_locations merely echoes the schema text, adding no new semantics.

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 ('Assign a menu to a theme location') and adds a concrete example ('put the Primary menu in the header's primary slot') that disambiguates the operation. It distinguishes implicitly from siblings like wp_set_menu_items or wp_create_menu, though it never names them explicitly.

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 gives clear prerequisite routing by telling the agent to obtain valid locations from wp_list_menu_locations, which is the key dependency for correct invocation. It stops short of any when-not or alternative-selection guidance, so it doesn't reach 5.

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