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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the description is not obligated to repeat those. It adds the behavioral nuance that this works against multiple dictionaries and handles partial words, but it does not disclose what the response looks like (e.g., list of matches) or any quirks like language handling. With annotations covering the safety profile, this is a standard adequate score.

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?

A single, front-loaded sentence with no filler. It states the verb first and includes only essential information (the languages and dictionary names). Every word earns its place.

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?

For a three-parameter autocomplete tool with no output schema, the description is minimally sufficient but leaves some gaps. It explains the core input (prefix) and the dictionary options, but does not clarify what the return format is, how limit behaves, or edge cases. Given the simplicity of the tool and the presence of annotations, this is adequate but not comprehensive.

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 0%, so the description must carry meaning for the parameters. It does explain that 'prefix' is a partial Hebrew/Aramaic word and lists the allowed dictionary values, which adds value beyond the raw schema. However, it neglects to explain 'limit' (e.g., max number of completions) and does not explicitly tie the quoted dictionary names to the 'dictionary' parameter, though it is implied.

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 purpose with a specific verb ('Autocomplete') and resource ('partial Hebrew/Aramaic word') against a named set of dictionaries. It distinguishes itself from the sibling 'dictionary_lookup' by implying it handles partial words rather than full lookups, and it lists the specific dictionaries involved.

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 conveys a clear context: use this when you have a partial Hebrew/Aramaic word needing completions. However, it does not explicitly mention alternatives or when not to use it (e.g., when you already have a complete word, use dictionary_lookup). This is a clear context without exclusions, 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.