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

Annotations already cover the safety profile (readOnly, non-open-world), and the description adds real behavioral detail: matching is by text or prefix, results are ranked with best match first, and omitting the table widens the search. It does not mention result caps or pagination, which is the main remaining gap.

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 action and followed by the routing guidance. The parenthetical about code_tables is dense but earns its place by resolving where table names come from.

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?

An output schema exists, so return values need not be explained; the description still usefully states ranking order. For a 2-param read tool with full schema coverage and annotations, only minor details (result limits, whether prefix vs. text matching differ) are 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 coverage is 100%, so both parameters are already documented with examples ('bygg or 433') and the omit-to-search-all behavior. The description's phrasing mirrors the schema rather than adding new meaning, so 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 ('find codes by text or code prefix') plus scope (code tables) and result ordering (best match first). It points at the describe tool for the table list, but does not explicitly contrast with lookup/fetch, which also sound like code-retrieval paths.

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 a clear directive ('use it instead of guessing codes') and tells the agent where the valid table names come from (describe's code_tables, or a coded filter field). No explicit when-not-to-use or contrast with the other lookup-style siblings, so it stops short of a 5.

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