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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It only mentions 'bounded' and the offset mechanism, but omits critical details such as what happens if offset exceeds file length, whether the file must already be UTF-8 or if it attempts conversion, error handling, and the effect of max_chars (e.g., hard cap, truncation behavior). These gaps leave an agent guessing about edge cases.

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 a single, tightly-worded sentence with no filler. The primary action is front-loaded, and the offset hint is appended as a concise usage note. Every word contributes value, and there is no redundancy or unnecessary detail.

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?

Despite having an output schema (so return format need not be explained), the description is incomplete for a tool with 3 parameters and no annotations. It fails to specify max_chars behavior (e.g., whether it returns fewer characters if the file is shorter), offset handling at file boundaries, encoding validation, or error conditions. An agent would need to experiment or assume defaults, which is risky in production workflows.

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 for undocumented parameters. It only indirectly explains offset_chars ('continue a large file') but says nothing about the meaning or constraints of max_chars (default 4000, but is it a strict max?) or path (what kind of paths are acceptable). This under-specification forces the agent to rely on schema types alone, which is insufficient for correct invocation.

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 states a specific verb (read) and a precise resource (bounded UTF-8 text chunk), and the phrase 'use offset_chars to continue a large file' clarifies the intended use of paging. This distinguishes it from siblings like read_binary_slice (binary vs text) and extract_printable_strings (different extraction purpose), making its function unmistakable even without inspecting the schema.

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 instruction 'use offset_chars to continue a large file' provides clear, actionable context for a specific scenario (reading large files in bounded chunks). It doesn't explicitly name alternative tools or when not to use this one, but the purpose statement already implies it's for text reading, and the offset guidance is a concrete usage directive.

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