technicals

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, but the description adds substantial behavioral context beyond that: data is computed from daily bars, readings are the latest defined value of each series, upstream paging happens 12 sessions at a time, and pagesFetched reports query cost. No contradiction exists between description and annotations.

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 tightly packed sentences with no filler: the first defines scope and indicators, the second gives usage guidance and return semantics, and the third covers performance and output metadata. It is appropriately sized and front-loaded with the most important information.

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 4-parameter read-only tool with no output schema, the description covers the essential selection criteria, return nature ('latest defined value', 'Returns NUMBERS'), and cost signal (pagesFetched). It is slightly light on the exact response envelope, but the schema and annotations cover the invocation side well, making this sufficient for correct use.

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 100%, so the baseline is 3. The description adds meaningful semantics around bars by explaining the pagination behavior and performance cost, which complements the schema's note that bars is ignored when from is given. It does not deeply elaborate to/from beyond schema, but the schema already documents those well.

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?

The description states a specific verb-resource pair ('Technical indicator readings for an IDX stock'), enumerates the exact indicators (SMA/EMA, RSI, MACD, Bollinger Bands, ATR, support/resistance), and explicitly contrasts itself with price_chart. An agent can immediately tell what this tool computes and how it differs from visual charting.

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 description gives explicit usage guidance: use it when you need numbers for reasoning versus price_chart for a picture. It also warns that deep history is paged and a large bars value is slow, helping agents decide on parameter magnitude. This is strong when-to-use and when-not-to-use guidance.

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