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

Annotations already establish that this is a read-only, idempotent, non-destructive, open-world call. The description adds useful behavioral context beyond that: the accepted input range, the cost per successful call, and an alternate HTTPS endpoint. It does not explain error behavior or payment mechanics in detail, so it is not quite a 5.

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 definition is front-loaded with the core behavior and examples, then adds range, pricing, and endpoint information. It is efficient overall, though the pricing and HTTPS endpoint sentences are operational rather than semantic and could be separated more cleanly.

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 single-parameter conversion tool with no output schema, the description supplies enough context to call it correctly: it defines the output format through examples, states the input range, and discloses cost. It could be more complete by naming alternatives or clarifying when this full-string tool is preferred over its siblings.

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 parameter meaning. It partly does by stating that n runs from 0 to 999999999999 and by referring to n as the number whose digits are produced, but the range largely duplicates the schema's min/max and it does not describe type or edge-case handling beyond the examples.

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 makes the tool's purpose clear: it produces the base -2 digit string for an input n, and concrete examples (0, 1, 2, 4, 6) remove ambiguity about the output format. It does not explicitly distinguish itself from siblings such as negabinary_bits, negabinary_digit, negabinary_decode, or negabinary_len, so it falls short of a 5.

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 says what the tool returns but gives no guidance on when to use it instead of the many sibling negabinary tools. An agent must infer that this is the full-string conversion tool rather than one of the specialized variants.

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