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

Annotations already declare readOnlyHint=true, but the description adds genuine behavioral context beyond that: the 'stored' flag semantics (false = showing default) and the '_row' identity that must be returned unchanged. That is useful non-obvious behavior an agent could not get from annotations or schema.

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?

Purpose is front-loaded and the extra rule is kept short. The prose is a little dense and awkwardly worded, but no sentence is wasted.

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 no output schema, the description carries the return-shape burden and does explain the keyed-by-field-name shape plus the 'stored' and '_row' fields. It also points to the fields-contract doc for deeper detail, leaving the definition reasonably complete for a read tool.

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%, so both parameters are already documented in the schema. The description reinforces 'one record or options page' but adds no format or selection syntax beyond the schema. Baseline 3 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 clear verb+resource (get field values) and scopes it to 'one record or of an options page', tying directly to the postId/options parameters. It also names the sibling set-field-values to disambiguate, though the phrasing is slightly convoluted.

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 names the counterpart tool set-field-values and gives a rule to read the fields-contract skill doc before the first call, which is real usage guidance. But it never contrasts against near siblings like get-fields or list-post-type-fields, so the when-to-use vs alternatives is only partially covered.

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