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

Annotations already declare a safe, idempotent read operation. The description adds strategic context: search large documents first and avoid rereading sufficient passages. It does not cover error behavior or return format, but with annotations covering safety, this is useful added value.

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?

Three sentences, front-loaded with the core action, followed by concise usage guidance and a caution. Every sentence earns its place with no redundancy.

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 tool with annotations, the description covers purpose and usage strategy but leaves key gaps: it does not explain what resourceId refers to or where to obtain it, nor how the line range parameters behave. Adequate but incomplete for correct invocation.

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 only vaguely implies startLine/endLine via 'bounded line range' and says nothing about resourceId, optionality of line bounds, or expected formats. It adds minimal meaning beyond the raw parameter names.

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 resource ('project context document') with scope ('bounded line range'). It distinguishes from search by advising to search large documents first, but does not explicitly name the search sibling or clarify differences from view/list.

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 clear when-to-use guidance: read short relevant documents directly, search large documents first, and do not reread sufficient search passages. It implies the alternative (search) but stops short of naming it or describing when not to use this tool.

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