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

Annotations already cover safety (readOnly, idempotent, non-destructive) and open-world scope. The description adds genuinely non-structured context: it withholds the reconciled value, source values, and derivation arithmetic, and signals a gated paid operation behind it. It does not cover failure/error semantics, so not 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?

Two dense sentences, front-loaded with what the tool is and followed by what it validates and what it withholds. No filler.

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 an output schema present, return-value detail is unnecessary, and the description covers scope, the operation it gates, and disclosure boundaries. It omits what happens when validation fails, which would help an agent interpret outcomes.

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% and each required parameter (cik, anchor_accession, metric, period_start, period_end) is already documented in the schema. The description only names the validated categories without adding format, syntax, or edge-case meaning beyond 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?

States a specific verb (applicability check / validates) on a defined resource (a quarterly financial-fact reconciliation), and explicitly ties itself to the sibling operation it precedes. The free/paid distinction plus the list of validated inputs lets an agent separate this from reconcile_financial_fact without opening either 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?

The framing as a free preflight for the $1 reconcile operation makes the when-to-use condition clear: call this before paying for reconciliation. No explicit when-not-to-use or named alternative is given, but the context is unmistakable.

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