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 covered and the bar is lower. The description adds one useful behavioral note - the output includes VC criteria matches including Mode VC ($1M-$5M initial checks) - but never clarifies the shape of the comparison result, whether the VC match is a filter on the inputs, or what happens with partial inputs.

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?

A single sentence with the comparison front-loaded and no filler. It is dense but not padded; the only weakness is that the trailing 'returns matching VC criteria' clause is crammed in without setup, making the sentence slightly run-on.

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 seven-parameter calculator with no output schema, the description should describe the returned comparison - it only alludes to 'matching venture capital criteria including Mode VC'. It also leaves unclear whether the tool merely computes metrics or actively screens the company against VC criteria, which is a meaningful distinction for an agent deciding whether to call it.

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 all seven parameters carry units, ranges, and defaults, so the schema does the semantic work. The description names the RBF concepts (factor fee, daily remittance, payback months, effective APR) but adds no syntax or interaction detail beyond the schema - e.g. it never says how gross_margin_pct or yoy_growth_pct feed the SAFE side of the comparison.

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 two specific resources: it 'compares' Shopify Capital RBF (factor fee, remittance rate, payback months, effective APR) against a Post-Money SAFE equity round. This clearly separates it from siblings like calc_safe_dilution or calc_saas_metrics. The secondary claim that it 'returns matching venture capital criteria' muddies the purpose slightly, since it blends a calculator with a VC-matching function without saying how the two relate.

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 names an audience ('Shopify and commerce-tech founders') but gives no when-to-use, when-not-to-use, or alternative guidance. Given siblings such as calc_fundraising_readiness, calc_safe_dilution, calc_term_sheet_waterfall, and apply_to_mode_vc, an agent has no stated basis for choosing this tool over those.

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