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

Beyond the readOnly/idempotent annotations, it discloses that no remote request is triggered, that data freshness is bounded by a roughly twice-daily scheduled check, that empty lists mean 'no update known at that check', and the required capability. That is exactly the context an agent needs before trusting the output.

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?

Front-loaded with the purpose and caching caveat, then the return shape, then the capability and forwarding note. Dense but every clause adds information; the AlphaBridge forwarding sentence is mildly off-topic for invocation decisions but still relevant scoping context.

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?

No output schema exists, and the description compensates by enumerating the returned fields for core, plugins and themes plus the meaning of empty lists. Combined with the freshness caveat and permission requirement, an agent can call and interpret this safely.

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?

Zero parameters, so the baseline is 4 and there is nothing further to disambiguate. The description instead spends that space on the return shape, which is appropriate.

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 and resource ('Report available core, plugin and theme updates') and immediately qualifies scope with 'as of WordPress's own last scheduled check'. Distinguishable at a glance from wp_update_core, wp_bulk_update_status and wp_list_plugins.

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?

Clearly frames this as a read-only, cached inspection step and states the 'Needs update_core' capability requirement. It doesn't explicitly say 'call this before wp_update_core/wp_install_plugin', so the alternative-selection guidance is implied rather than stated.

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