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

Annotations already declare a safe read, but the description adds substantive context the annotations cannot: the response includes the check-progress journal (from what, to what, who, why), ordered newest first, plus creation and edit timestamps, and it discloses the permission model. That is meaningful behavioral disclosure beyond the hints.

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?

Purpose and the list_sources alternative are front-loaded, then return contents, then addressing forms. It is dense with em-dashes and long clauses, so it is efficient but slightly run-on rather than crisp.

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?

With no output schema, the description carries the burden of describing the return value, and it does so concretely (journal entries with before/after, actor, reason, ordering, created/edited stamps). Combined with the access rule and identifier formats, an agent has everything needed to call it 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?

Schema coverage is 100%, so the baseline is 3, but the description earns more by enumerating the identifier shapes accepted by 'source' — arXiv IDs, DOI strings and doi.org URLs, MR numbers, Zbl numbers, ISBNs — which the schema only gestures at with 'an identifier it has'.

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?

Names a specific verb and resource — retrieve one source of a project together with its journal — and explicitly points to the sibling list_sources for the collection case. An agent can distinguish this from list_sources and set_source/delete_source without opening 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?

Explicitly routes enumeration to list_sources and states the access condition ('Anybody who sees the project'), which is real guidance for whether the call will succeed. It stops short of naming when to prefer this over set_source or delete_source, so usage is clear but not fully delimited.

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