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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses the auth prerequisite (approved AlertForge account, OAuth flow), that calls are free and spend no credits, and that it returns a single-use 24-hour plan with exact cost. This is rich context the annotations do not carry.

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-loads the auth requirement and then proceeds to cost/workflow details; nearly every sentence earns its place. Slightly dense with setup URL and multiple clauses, but well structured.

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 compensates by describing the return (single-use 24-hour plan and exact cost) and the downstream confirmation step. For a 3-param planning tool it covers everything an agent needs to call it correctly.

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 all three parameters. The description nonetheless deepens the mode semantics ('small change to the same character' vs 'replacing it while preserving the rest pixel-for-pixel'), adding marginal value over the schema's own enum descriptions.

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 action (prices a character-region change on an existing Style Sheet), clarifies it is a no-credit planning step, and distinguishes it from the sibling create_style_sheet_character_edit by name. An agent can tell it apart from plan_* siblings readily.

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?

Explicitly routes mode=edit for small same-character changes versus mode=redesign for replacing the character while preserving the rest pixel-for-pixel, and gives the workflow rule: show the quote and obtain confirmation before calling create_style_sheet_character_edit.

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