ddb_character_lookup

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

Annotations already declare readOnlyHint and openWorldHint, so the safe-read nature is covered. The description adds valuable context about the login requirement and partial/fuzzy matching behavior. It does not describe return format, but the term 'full description' implies the output sufficiently for a lookup tool.

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 three tightly written sentences: first states the core function, second gives matching behavior with concrete examples, third clarifies parameters and auth. No wasted words, and the key information is front-loaded.

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?

Given the tool's moderate complexity, the description covers the essential aspects: what it does, matching behavior, parameter alternatives, and login prerequisite. With no output schema, a brief note on return structure would elevate it further, but 'full description' is a reasonable indicator. The readOnly annotation reduces the need for safety caveats.

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 the baseline is 3. The description adds the 'either/or' relationship between character_id and character_name, which the schema does not explicitly state. It also reinforces the name parameter's fuzzy matching with an example, though that is already in the schema.

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?

The description clearly states the tool's verb ('look up') and resource ('full description of a spell, feat, class feature, subclass feature, racial trait, background feature, or equipped item by name'). It distinguishes itself from sibling tools by its character-specific scope and cross-category coverage.

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 explicitly states the login prerequisite ('run ddb_login first') and clarifies that character_id or character_name can be used as alternatives. However, it does not directly compare itself to specialized search tools like ddb_search_spells, so there is no explicit when-not-to-use guidance.

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