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

With no annotations, the description carries the full burden. It does disclose two behavioral traits beyond the schema: result ordering ('newest first') and the breadth of the merge across six event categories. It does not state that this is a read-only operation, whether it spans all time by default, or how pagination behaves despite a cursor parameter.

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?

One sentence, front-loaded with the scope and followed by the concrete contents and ordering. Nothing wasted and nothing buried.

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 annotations, no output schema, and three undocumented parameters including a cursor, the description leaves the agent guessing about pagination and the shape of returned timeline entries. For an aggregating feed tool returning heterogeneous record types, this is under-specified.

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 description coverage is 0%, so the description must compensate and does not. It never mentions limit, cursor, or pagination semantics, even though 'newest first' plus cursor/limit implies a paged feed where an agent must loop on the cursor to get full history. Only the customer_id requirement is inferable from context.

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 resource (a customer's full activity history) and enumerates the event types included (requests, jobs, quotes, signatures, invoices, payments), which is more concrete than a bare 'get timeline'. It is distinguishable from customers_get or customers_statement by the word 'everything', though the description never names those siblings explicitly.

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?

Usage is implied: this is the aggregate activity feed for one customer, useful for 'what's the status/history here' questions. But there is no explicit when-to-use, no guidance on when customers_statement, customers_get, quotes_activity or audit_list would be better, and no exclusions.

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