fetch_sources

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: the ordered fallback chain, that text is extracted with page numbers and indexed, and that the run reports missing, paywalled, and title-mismatched PDFs. It stops short of stating the side effects explicitly (files written to disk, index mutation, possible network calls when download is enabled) or permissions/rate-limit considerations.

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?

Two dense sentences with no wasted words; the resolution order and the reporting outcome are both front-loaded. Every clause earns its place by conveying either behavior or output content.

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 two-param, no-output-schema tool with no annotations, the description adequately covers scope, approach, and what gets reported back. It could add a note on side effects (persisted index/PDF files) to be fully complete for a state-mutating batch operation.

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 both parameters (keys, download) are already documented in the schema, including the open-access repositories relevant to download. The description adds no syntax or format detail for `keys` beyond what the schema provides, so the baseline 3 applies.

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 specific verbs and resources ('Locate the PDF of each cited reference', 'extract its text ... and index it'), and spells out the resolution order (bib `file` field → PDF folders → Zotero storage → open-access repositories). This clearly distinguishes it from siblings like attach_pdf (manual attach) and read_source (read a single source), without needing to open any 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 multi-source fallback chain implies this is the batch-acquisition tool, and reporting on missing/paywalled sources hints at a verification workflow context. However, it never explicitly states when to use this versus attach_pdf or read_source, nor any exclusions or prerequisites (e.g., when to prefer manual attachment).

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