measure_color

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

With no annotations provided, the description carries the behavioral transparency burden. It explains the calculation, the normalization by zone height, the expected output range, and the interpretation of higher vs. lower values. It does not explicitly state that the tool has no side effects, but 'measure' plus 'Returns a value' strongly implies a read-only operation.

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?

The description is compact, front-loaded with the primary purpose, and each sentence adds meaningful detail: formula, normalization, output range, and interpretation. There is no filler or repetition.

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 simple measurement tool with no output schema, the description adequately covers what is returned and how to interpret it. However, the missing parameter semantics and lack of differentiation from sibling measurement tools leave an agent with some uncertainty about optional inputs and alternative tool selection.

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 0%, so the description must compensate, but it never mentions glyph_name or master_id. 'Single glyph' weakly maps to glyph_name, yet master_id is entirely unexplained, including its optional role and default-empty behavior.

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: 'Measure the ink density (typographic color) of a single glyph.' It defines the metric precisely with a formula and normalization rule, and distinguishes this from sibling tools like compare_color or audit_font_color by emphasizing a single glyph measurement.

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 implies usage: call this whenever you need the ink density of one glyph. However, it gives no explicit guidance about when to prefer this over alternatives such as compare_color or audit_font_color, and no exclusions or prerequisites are stated.

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