Create GST invoice PDF

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

Annotations declare readOnlyHint=false, openWorldHint=false, destructiveHint=false, so the agent already knows this is a local, non-destructive write. The description adds real context beyond that: it states the output artifact (a PDF written to the user's computer), that it returns the file path plus the tax breakdown, and the anti-fabrication rule for missing party data. It stops short of saying what happens on file-name collision or whether an existing PDF is overwritten.

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 sentences, front-loaded with the action and artifact, then the return value, then the guardrail. Every clause does work: scope, contents, return, and the do-not-invent rule. No filler or restatement of the title.

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 13-parameter, nested-object tool with no output schema, describing the return value is the right instinct, but 'the tax breakdown' is left vague — an agent cannot tell whether it gets a per-line CGST/SGST/IGST split or just totals. It also omits filesystem behavior such as creating a missing output_dir or handling name collisions. Adequate, but not fully sufficient for this complexity.

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 only 54% across 13 parameters, so the description carries some burden. It does map several parameters to document fields (place of supply, reverse charge, bank/UPI details, amount in words) and, importantly, describes return values since no output schema exists. But it adds no semantics for prices_include_gst, gst_rate/cess_rate interplay, or how ship_to differs from buyer — the highest-risk ambiguities are left to the schema alone.

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?

The description opens with a specific verb and resource: 'Generate a GST-compliant tax invoice as a PDF on the user's computer', then enumerates the document's contents (HSN/SAC, tax split, place of supply, reverse charge, amount in words). This clearly separates it from siblings like calculate_gst, amount_in_words, or lookup_hsn_sac, which compute fragments rather than produce the finished document.

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?

It gives one concrete operating guideline — ask the user for missing supplier or buyer details rather than inventing them — which is genuinely useful for a document-generation tool. However, it never states when to prefer this over calculate_gst or the lookup tools that supply its inputs, and offers no exclusions or prerequisites beyond that single instruction. Usage is implied rather than routed.

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