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

Goes well beyond the annotations, which only declare read-only/idempotent/non-destructive. The description discloses that it will not invent circumstances, emits bracketed placeholders for missing facts, is quota-charged as an explanation, and answers identical input from cache for free. Those are exactly the behavioral traits an agent needs before calling.

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 transformation in the first sentence, then proceeds to constraints and cost. Every sentence carries information, though the passage is dense and runs long relative to the schema's self-documentation.

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 no output schema, the description carries the return-value burden and does so adequately: it says the output is reason text with bracketed placeholders for gaps. It doesn't specify the exact return shape (plain string vs. structured), which is the only meaningful residual gap for a 4-parameter drafting tool.

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 coverage is 100%, so the schema already documents jurisdiction, circumstances, expectedReadyBy and whyItStoppedTheAccounts, including 'Never estimate it'. The description reinforces the facts-only constraint on circumstances but adds no new syntax, format or selection detail. Baseline 3 is appropriate.

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 and output (turn a factual account into the reason text for an extension application) and names the domain framing (the terms the registrar applies). It also draws the boundary against adjacent tools: 'does not submit the application and does not file accounts', which separates it from check_filing_extension and save_filing in the sibling list.

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 clear operating context: the practitioner must ask the person what happened rather than supplying facts, and the person must check every sentence before certifying it. The 'does not submit / does not file' clause functions as an explicit when-not. No sibling tool is named as the alternative, so it stops short of a full 5.

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