aethis_decide

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

Annotations only declare read-only/non-destructive/open-world; the description goes further by disclosing the three outcome states (eligible/not_eligible/undetermined), the undetermined payload (next_question, optimal_path), optional trace and explanation, and the API-key requirement per mode. With no output schema, this return-value disclosure is the primary behavioral value and it is covered.

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?

Front-loaded with the core action and the either/or constraint, then builds outward to mode semantics, return states, and auth. Every sentence carries distinct information; nothing is repeated or padded.

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 six-parameter, nested-object tool with no output schema, the description supplies the missing pieces: mutual exclusivity of the two ID modes, the auth difference between them, and the shape of the non-success outcome. Nothing an agent needs to call it correctly is absent.

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 baseline is 3; the description adds conceptual semantics beyond the schema's field-level text — that a rulebook composes rulesets via outcome_logic and that exactly one of the two IDs must be supplied. It does not add syntax or format detail for field_values beyond deferring to aethis_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?

States a specific verb+resource (evaluate eligibility) and immediately disambiguates the two modes of operation: single published ruleset vs composed rulebook. The examples (`aethis/uk-fsm` vs `aethis/uk-fsm/child-eligibility`) make the distinction concrete and let an agent separate this from sibling tools like aethis_schema or aethis_next_question.

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?

Explicit routing guidance: 'Provide exactly one,' plus the decision rule — use a rulebook for the whole-form decision, a ruleset for one section in isolation. It also states the auth precondition that selects between modes (rulebook always needs an API key; ruleset can be anonymous against public rulesets).

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