log_fields

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

Annotations already cover read-only/idempotent/destructive hints. The description adds valuable behavioral details beyond annotations: the exact envelope shape, that every matching field is returned, and that truncated is always false — meaning the result is a complete list, not a page. This is helpful for an agent deciding whether to paginate.

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?

The description is front-loaded with '[READ]' and the primary action, then flows logically through purpose, return format, and pagination behavior. Almost every sentence earns its place, though the trailing 'Read-only' is redundant given the '[READ]' prefix and annotations.

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?

Despite having no output schema, the description explains the return envelope, field item shape, and pagination behavior, so an agent knows exactly what to expect. Combined with the fully documented schema and strong annotations, nothing needed to invoke the tool correctly is missing.

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 the schema already documents both optional parameters well. The description adds the important 'no limit / complete list' nuance but does not need to repeat parameter meaning; 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 specific verb ('List'), the resource ('extracted fields'), and the purpose ('available to use in query filters'). Explicitly names the downstream consumers (log_search / log_aggregate), making the tool's role clear and distinguishable from siblings.

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?

Gives clear context: 'Use this to discover valid field names before filtering log_search / log_aggregate.' It does not explicitly describe when not to use it or mention alternatives, but no sibling tool performs field discovery, so the guidance is sufficient.

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