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

The annotations only declare readOnlyHint=true, so the description's note that PDFs and images are returned as the actual document with correct table and scan rendering adds meaningful behavioral context. There is no contradiction between the read-only annotation and the described behavior.

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 focused sentences front-load the purpose, then add the use case, special rendering behavior, and lookup guidance. No sentence is redundant or wasted.

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 read-only file-reading tool, the description covers when to use it, how to resolve the file, which parameter to pass, and how PDFs/images behave. It is complete enough to guide correct invocation even without an output schema.

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 baseline is 3. The description reinforces the object_id-vs-name choice and the search_graph_objects workflow, but it does not materially add parameter semantics beyond what the schema already documents.

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 reads the content of a user-uploaded file in the Second Brain, with the verb and resource both specific. It distinguishes this from web-page or Obsidian-note readers by narrowing scope to uploaded documents and by naming search_graph_objects as the way to locate them.

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 explicitly says to use this when the answer may live in an uploaded document, which gives a clear triggering context. It also provides the lookup workflow with search_graph_objects, but it does not explicitly state when not to use it or name alternative reading tools such as read_web_page.

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