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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-structured context: it runs against local WordPress authentication and needs no WooCommerce REST API keys, which matters for setup expectations. It does not say what is returned when the metaKey is absent, keeping it below a 5.

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 sentences, front-loaded with the operation and then the authentication note. The clause about mirroring the `get_product_meta` server method is internal implementation detail that does little to help an agent select or invoke the tool, but it is brief and does not obscure the core statement.

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?

With three fully documented parameters, a read-only annotation set, and no output schema, the definition covers selection adequately. However, since there is no output schema, the description should hint at the shape of the returned metadata (key/value pairs, empty result on missing key) and it does not.

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 each of the three parameters is already documented, including the site_id warning to call list_sites first. The description only echoes the optional meta-key filter and adds no format, casing, or matching semantics beyond the schema — the baseline 3 applies.

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 ("Retrieves WooCommerce product metadata") plus the optional filter, which cleanly separates it from the update/delete_product_meta siblings that share the same resource. It stops short of naming those siblings explicitly, so it is clear but not maximally differentiated.

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 implies the read use case (optionally narrowing by meta key) and states an authentication precondition. It never says when to prefer this over wc_get_product or wc_get_product_variation, nor what to do when metaKey is unknown — the agent must infer the boundaries.

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