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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without description help. The description adds only the returned identity fields (id, source, revision) and the one-remit scope — useful, but nothing about scoring, pagination or limits beyond the annotations.

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 tight clauses front-load the read scope and follow with concrete use cases and the downstream call, with no redundant restatement of the title or schema.

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?

With annotations supplying the safety profile, a full schema and an output schema covering return shape, the description need only justify existence and usage — which it does. Minor gap: it does not say whether results can be empty because bookKey was left blank or whether the window caps result size.

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%: type enum, bookKey remit key, and the YYYY-MM-DD starts/ends bounds are all documented in the schema. The description's 'one remit in a date window' and 'named season into dates' reinforce but do not extend those semantics, so the baseline of 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 (read) and resource (trading, promotion or custom calendar entries) plus the scope (one remit, a date window) and even the fields returned (id, source, revision). It also names the enum values, so the agent can distinguish this from catalogue, product, sales or document siblings without opening the schema.

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 concrete use cases — key dates, promotions, holidays, trading periods — and an explicit sequencing rule: resolve a named season into dates before calling recall_decisions. There is no explicit when-not or alternative-calendar tool, but the intended context is unambiguous.

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