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

The description discloses the behavioral trait of being a read-only lookup ('Look up'), consistent with the readOnlyHint annotation. It also specifies what data is returned (Arabic, transliteration, English, Bengali), adding value beyond the annotation. No contradictions or missing behavioral traits.

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 two sentences, front-loaded with the purpose, and every clause provides necessary information. No wasted words. Structure is optimal for quick reading.

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 read-only tool with no output schema, the description completely covers all input modes and output content. No missing information given the tool's 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 coverage is 100% with descriptions for both parameters. The description adds significant meaning by explaining the interplay: 'Give a number for one name, a search term... or neither to get all 99.' This clarifies the optionality and intended usage beyond what the schema alone provides.

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 clearly states the tool's purpose ('Look up the 99 Names of Allah'), specifies the output (Arabic, transliteration, English, Bengali), and distinguishes three usage modes (by number, search, or all). This is a precise verb+resource definition that differentiates from sibling tools like get_prayer_times or get_quran_audio.

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 gives explicit guidance on when to use each parameter: 'Give a number for one name, a search term to match by meaning or transliteration, or neither to get all 99.' This covers all usage scenarios and implicitly tells the agent when not to use alternatives. No exclusions are needed.

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