Read chunk

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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds real context beyond that: it works on both page and file chunks, and it names the file-chunk citation fields (file_name, parent page_id, download_url, share_url) an agent will encounter. It does not discuss error cases or missing-chunk behavior, keeping it short of a 5.

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 purpose and the granularity/alternative rule before the file-chunk detail. The parenthetical file-citation list is dense but earns its place as invocation-relevant context; slight wordiness keeps it from a 5.

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?

An output schema exists, so return values need not be explained, and the description still covers granularity, the alternative tool, the source constraint, and the file-chunk case. For a one-parameter read tool this is complete enough to call correctly.

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?

There is a single parameter and schema description coverage is 100%, so the schema already documents chunk_id fully. The description's phrase 'from a `research` source' roughly restates the schema's 'chunk id from a research result' and adds no format or sourcing detail beyond it. Baseline 3 is appropriate.

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+resource ('Fetch one chunk's full section text by chunk_id') and pins down the scope ('for a page OR a file chunk'). It also explicitly distinguishes itself from get_page ('Middle granularity... for the whole page use get_page'), so an agent can route correctly without opening either 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 an explicit when-to-use ('expand a single cited section'), an explicit when-not/alternative ('for the whole page use get_page'), and a source precondition ('from a `research` source'). Nothing about selection is left to inference.

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