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

Annotations only declare readOnlyHint=true. The description adds substantial behavioral context beyond that: format-dependent return behavior (PDFs/images returned as the actual document, docx/pptx/xlsx as extracted text, text/Markdown as written) and a hard truncation limit around 200 KB. This is exactly the kind of detail an agent cannot infer elsewhere.

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?

Front-loaded with the primary action and densely informational, with every sentence carrying weight (usage trigger, format behavior, truncation, lookup instructions). It reads as one long paragraph rather than clearly separated concerns, which slightly hurts scanability but wastes little.

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 tool with no output schema, the description fully covers what the agent needs: when to use it, how to locate the file, what comes back per format, and the truncation cap. No essential information is missing.

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 baseline is 3, but the description goes further by explaining the relationship between the two params: pass object_id (obtained from search_graph_objects with type 'file'), or alternatively pass part of the filename as name. That clarifies the intended lookup flow beyond the schema's field descriptions.

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?

States a specific verb and resource: 'Read the content of a file the user uploaded,' scoped to documents in the user's Second Brain. This clearly differentiates it from siblings like read_artifact, get_graph_object, and read_web_page, which the agent can rule out without opening a 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?

Gives a concrete when-to-use trigger ('when the answer may live in a document... schedules, itineraries, contracts, exports, scans, decks') and a workflow prerequisite ('find the file first with search_graph_objects'). It stops short of naming explicit alternatives or when-not-to-use cases among the read/artifact siblings.

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